Index: frontend/node_modules/readable-stream/lib/_stream_duplex.js
===================================================================
--- frontend/node_modules/readable-stream/lib/_stream_duplex.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/_stream_duplex.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,126 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// a duplex stream is just a stream that is both readable and writable.
+// Since JS doesn't have multiple prototypal inheritance, this class
+// prototypally inherits from Readable, and then parasitically from
+// Writable.
+
+'use strict';
+
+/*<replacement>*/
+var objectKeys = Object.keys || function (obj) {
+  var keys = [];
+  for (var key in obj) keys.push(key);
+  return keys;
+};
+/*</replacement>*/
+
+module.exports = Duplex;
+var Readable = require('./_stream_readable');
+var Writable = require('./_stream_writable');
+require('inherits')(Duplex, Readable);
+{
+  // Allow the keys array to be GC'ed.
+  var keys = objectKeys(Writable.prototype);
+  for (var v = 0; v < keys.length; v++) {
+    var method = keys[v];
+    if (!Duplex.prototype[method]) Duplex.prototype[method] = Writable.prototype[method];
+  }
+}
+function Duplex(options) {
+  if (!(this instanceof Duplex)) return new Duplex(options);
+  Readable.call(this, options);
+  Writable.call(this, options);
+  this.allowHalfOpen = true;
+  if (options) {
+    if (options.readable === false) this.readable = false;
+    if (options.writable === false) this.writable = false;
+    if (options.allowHalfOpen === false) {
+      this.allowHalfOpen = false;
+      this.once('end', onend);
+    }
+  }
+}
+Object.defineProperty(Duplex.prototype, 'writableHighWaterMark', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._writableState.highWaterMark;
+  }
+});
+Object.defineProperty(Duplex.prototype, 'writableBuffer', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._writableState && this._writableState.getBuffer();
+  }
+});
+Object.defineProperty(Duplex.prototype, 'writableLength', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._writableState.length;
+  }
+});
+
+// the no-half-open enforcer
+function onend() {
+  // If the writable side ended, then we're ok.
+  if (this._writableState.ended) return;
+
+  // no more data can be written.
+  // But allow more writes to happen in this tick.
+  process.nextTick(onEndNT, this);
+}
+function onEndNT(self) {
+  self.end();
+}
+Object.defineProperty(Duplex.prototype, 'destroyed', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    if (this._readableState === undefined || this._writableState === undefined) {
+      return false;
+    }
+    return this._readableState.destroyed && this._writableState.destroyed;
+  },
+  set: function set(value) {
+    // we ignore the value if the stream
+    // has not been initialized yet
+    if (this._readableState === undefined || this._writableState === undefined) {
+      return;
+    }
+
+    // backward compatibility, the user is explicitly
+    // managing destroyed
+    this._readableState.destroyed = value;
+    this._writableState.destroyed = value;
+  }
+});
Index: frontend/node_modules/readable-stream/lib/_stream_passthrough.js
===================================================================
--- frontend/node_modules/readable-stream/lib/_stream_passthrough.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/_stream_passthrough.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,37 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// a passthrough stream.
+// basically just the most minimal sort of Transform stream.
+// Every written chunk gets output as-is.
+
+'use strict';
+
+module.exports = PassThrough;
+var Transform = require('./_stream_transform');
+require('inherits')(PassThrough, Transform);
+function PassThrough(options) {
+  if (!(this instanceof PassThrough)) return new PassThrough(options);
+  Transform.call(this, options);
+}
+PassThrough.prototype._transform = function (chunk, encoding, cb) {
+  cb(null, chunk);
+};
Index: frontend/node_modules/readable-stream/lib/_stream_readable.js
===================================================================
--- frontend/node_modules/readable-stream/lib/_stream_readable.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/_stream_readable.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,1027 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+'use strict';
+
+module.exports = Readable;
+
+/*<replacement>*/
+var Duplex;
+/*</replacement>*/
+
+Readable.ReadableState = ReadableState;
+
+/*<replacement>*/
+var EE = require('events').EventEmitter;
+var EElistenerCount = function EElistenerCount(emitter, type) {
+  return emitter.listeners(type).length;
+};
+/*</replacement>*/
+
+/*<replacement>*/
+var Stream = require('./internal/streams/stream');
+/*</replacement>*/
+
+var Buffer = require('buffer').Buffer;
+var OurUint8Array = (typeof global !== 'undefined' ? global : typeof window !== 'undefined' ? window : typeof self !== 'undefined' ? self : {}).Uint8Array || function () {};
+function _uint8ArrayToBuffer(chunk) {
+  return Buffer.from(chunk);
+}
+function _isUint8Array(obj) {
+  return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
+}
+
+/*<replacement>*/
+var debugUtil = require('util');
+var debug;
+if (debugUtil && debugUtil.debuglog) {
+  debug = debugUtil.debuglog('stream');
+} else {
+  debug = function debug() {};
+}
+/*</replacement>*/
+
+var BufferList = require('./internal/streams/buffer_list');
+var destroyImpl = require('./internal/streams/destroy');
+var _require = require('./internal/streams/state'),
+  getHighWaterMark = _require.getHighWaterMark;
+var _require$codes = require('../errors').codes,
+  ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
+  ERR_STREAM_PUSH_AFTER_EOF = _require$codes.ERR_STREAM_PUSH_AFTER_EOF,
+  ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
+  ERR_STREAM_UNSHIFT_AFTER_END_EVENT = _require$codes.ERR_STREAM_UNSHIFT_AFTER_END_EVENT;
+
+// Lazy loaded to improve the startup performance.
+var StringDecoder;
+var createReadableStreamAsyncIterator;
+var from;
+require('inherits')(Readable, Stream);
+var errorOrDestroy = destroyImpl.errorOrDestroy;
+var kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];
+function prependListener(emitter, event, fn) {
+  // Sadly this is not cacheable as some libraries bundle their own
+  // event emitter implementation with them.
+  if (typeof emitter.prependListener === 'function') return emitter.prependListener(event, fn);
+
+  // This is a hack to make sure that our error handler is attached before any
+  // userland ones.  NEVER DO THIS. This is here only because this code needs
+  // to continue to work with older versions of Node.js that do not include
+  // the prependListener() method. The goal is to eventually remove this hack.
+  if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (Array.isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
+}
+function ReadableState(options, stream, isDuplex) {
+  Duplex = Duplex || require('./_stream_duplex');
+  options = options || {};
+
+  // Duplex streams are both readable and writable, but share
+  // the same options object.
+  // However, some cases require setting options to different
+  // values for the readable and the writable sides of the duplex stream.
+  // These options can be provided separately as readableXXX and writableXXX.
+  if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex;
+
+  // object stream flag. Used to make read(n) ignore n and to
+  // make all the buffer merging and length checks go away
+  this.objectMode = !!options.objectMode;
+  if (isDuplex) this.objectMode = this.objectMode || !!options.readableObjectMode;
+
+  // the point at which it stops calling _read() to fill the buffer
+  // Note: 0 is a valid value, means "don't call _read preemptively ever"
+  this.highWaterMark = getHighWaterMark(this, options, 'readableHighWaterMark', isDuplex);
+
+  // A linked list is used to store data chunks instead of an array because the
+  // linked list can remove elements from the beginning faster than
+  // array.shift()
+  this.buffer = new BufferList();
+  this.length = 0;
+  this.pipes = null;
+  this.pipesCount = 0;
+  this.flowing = null;
+  this.ended = false;
+  this.endEmitted = false;
+  this.reading = false;
+
+  // a flag to be able to tell if the event 'readable'/'data' is emitted
+  // immediately, or on a later tick.  We set this to true at first, because
+  // any actions that shouldn't happen until "later" should generally also
+  // not happen before the first read call.
+  this.sync = true;
+
+  // whenever we return null, then we set a flag to say
+  // that we're awaiting a 'readable' event emission.
+  this.needReadable = false;
+  this.emittedReadable = false;
+  this.readableListening = false;
+  this.resumeScheduled = false;
+  this.paused = true;
+
+  // Should close be emitted on destroy. Defaults to true.
+  this.emitClose = options.emitClose !== false;
+
+  // Should .destroy() be called after 'end' (and potentially 'finish')
+  this.autoDestroy = !!options.autoDestroy;
+
+  // has it been destroyed
+  this.destroyed = false;
+
+  // Crypto is kind of old and crusty.  Historically, its default string
+  // encoding is 'binary' so we have to make this configurable.
+  // Everything else in the universe uses 'utf8', though.
+  this.defaultEncoding = options.defaultEncoding || 'utf8';
+
+  // the number of writers that are awaiting a drain event in .pipe()s
+  this.awaitDrain = 0;
+
+  // if true, a maybeReadMore has been scheduled
+  this.readingMore = false;
+  this.decoder = null;
+  this.encoding = null;
+  if (options.encoding) {
+    if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
+    this.decoder = new StringDecoder(options.encoding);
+    this.encoding = options.encoding;
+  }
+}
+function Readable(options) {
+  Duplex = Duplex || require('./_stream_duplex');
+  if (!(this instanceof Readable)) return new Readable(options);
+
+  // Checking for a Stream.Duplex instance is faster here instead of inside
+  // the ReadableState constructor, at least with V8 6.5
+  var isDuplex = this instanceof Duplex;
+  this._readableState = new ReadableState(options, this, isDuplex);
+
+  // legacy
+  this.readable = true;
+  if (options) {
+    if (typeof options.read === 'function') this._read = options.read;
+    if (typeof options.destroy === 'function') this._destroy = options.destroy;
+  }
+  Stream.call(this);
+}
+Object.defineProperty(Readable.prototype, 'destroyed', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    if (this._readableState === undefined) {
+      return false;
+    }
+    return this._readableState.destroyed;
+  },
+  set: function set(value) {
+    // we ignore the value if the stream
+    // has not been initialized yet
+    if (!this._readableState) {
+      return;
+    }
+
+    // backward compatibility, the user is explicitly
+    // managing destroyed
+    this._readableState.destroyed = value;
+  }
+});
+Readable.prototype.destroy = destroyImpl.destroy;
+Readable.prototype._undestroy = destroyImpl.undestroy;
+Readable.prototype._destroy = function (err, cb) {
+  cb(err);
+};
+
+// Manually shove something into the read() buffer.
+// This returns true if the highWaterMark has not been hit yet,
+// similar to how Writable.write() returns true if you should
+// write() some more.
+Readable.prototype.push = function (chunk, encoding) {
+  var state = this._readableState;
+  var skipChunkCheck;
+  if (!state.objectMode) {
+    if (typeof chunk === 'string') {
+      encoding = encoding || state.defaultEncoding;
+      if (encoding !== state.encoding) {
+        chunk = Buffer.from(chunk, encoding);
+        encoding = '';
+      }
+      skipChunkCheck = true;
+    }
+  } else {
+    skipChunkCheck = true;
+  }
+  return readableAddChunk(this, chunk, encoding, false, skipChunkCheck);
+};
+
+// Unshift should *always* be something directly out of read()
+Readable.prototype.unshift = function (chunk) {
+  return readableAddChunk(this, chunk, null, true, false);
+};
+function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
+  debug('readableAddChunk', chunk);
+  var state = stream._readableState;
+  if (chunk === null) {
+    state.reading = false;
+    onEofChunk(stream, state);
+  } else {
+    var er;
+    if (!skipChunkCheck) er = chunkInvalid(state, chunk);
+    if (er) {
+      errorOrDestroy(stream, er);
+    } else if (state.objectMode || chunk && chunk.length > 0) {
+      if (typeof chunk !== 'string' && !state.objectMode && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
+        chunk = _uint8ArrayToBuffer(chunk);
+      }
+      if (addToFront) {
+        if (state.endEmitted) errorOrDestroy(stream, new ERR_STREAM_UNSHIFT_AFTER_END_EVENT());else addChunk(stream, state, chunk, true);
+      } else if (state.ended) {
+        errorOrDestroy(stream, new ERR_STREAM_PUSH_AFTER_EOF());
+      } else if (state.destroyed) {
+        return false;
+      } else {
+        state.reading = false;
+        if (state.decoder && !encoding) {
+          chunk = state.decoder.write(chunk);
+          if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false);else maybeReadMore(stream, state);
+        } else {
+          addChunk(stream, state, chunk, false);
+        }
+      }
+    } else if (!addToFront) {
+      state.reading = false;
+      maybeReadMore(stream, state);
+    }
+  }
+
+  // We can push more data if we are below the highWaterMark.
+  // Also, if we have no data yet, we can stand some more bytes.
+  // This is to work around cases where hwm=0, such as the repl.
+  return !state.ended && (state.length < state.highWaterMark || state.length === 0);
+}
+function addChunk(stream, state, chunk, addToFront) {
+  if (state.flowing && state.length === 0 && !state.sync) {
+    state.awaitDrain = 0;
+    stream.emit('data', chunk);
+  } else {
+    // update the buffer info.
+    state.length += state.objectMode ? 1 : chunk.length;
+    if (addToFront) state.buffer.unshift(chunk);else state.buffer.push(chunk);
+    if (state.needReadable) emitReadable(stream);
+  }
+  maybeReadMore(stream, state);
+}
+function chunkInvalid(state, chunk) {
+  var er;
+  if (!_isUint8Array(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
+    er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer', 'Uint8Array'], chunk);
+  }
+  return er;
+}
+Readable.prototype.isPaused = function () {
+  return this._readableState.flowing === false;
+};
+
+// backwards compatibility.
+Readable.prototype.setEncoding = function (enc) {
+  if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
+  var decoder = new StringDecoder(enc);
+  this._readableState.decoder = decoder;
+  // If setEncoding(null), decoder.encoding equals utf8
+  this._readableState.encoding = this._readableState.decoder.encoding;
+
+  // Iterate over current buffer to convert already stored Buffers:
+  var p = this._readableState.buffer.head;
+  var content = '';
+  while (p !== null) {
+    content += decoder.write(p.data);
+    p = p.next;
+  }
+  this._readableState.buffer.clear();
+  if (content !== '') this._readableState.buffer.push(content);
+  this._readableState.length = content.length;
+  return this;
+};
+
+// Don't raise the hwm > 1GB
+var MAX_HWM = 0x40000000;
+function computeNewHighWaterMark(n) {
+  if (n >= MAX_HWM) {
+    // TODO(ronag): Throw ERR_VALUE_OUT_OF_RANGE.
+    n = MAX_HWM;
+  } else {
+    // Get the next highest power of 2 to prevent increasing hwm excessively in
+    // tiny amounts
+    n--;
+    n |= n >>> 1;
+    n |= n >>> 2;
+    n |= n >>> 4;
+    n |= n >>> 8;
+    n |= n >>> 16;
+    n++;
+  }
+  return n;
+}
+
+// This function is designed to be inlinable, so please take care when making
+// changes to the function body.
+function howMuchToRead(n, state) {
+  if (n <= 0 || state.length === 0 && state.ended) return 0;
+  if (state.objectMode) return 1;
+  if (n !== n) {
+    // Only flow one buffer at a time
+    if (state.flowing && state.length) return state.buffer.head.data.length;else return state.length;
+  }
+  // If we're asking for more than the current hwm, then raise the hwm.
+  if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
+  if (n <= state.length) return n;
+  // Don't have enough
+  if (!state.ended) {
+    state.needReadable = true;
+    return 0;
+  }
+  return state.length;
+}
+
+// you can override either this method, or the async _read(n) below.
+Readable.prototype.read = function (n) {
+  debug('read', n);
+  n = parseInt(n, 10);
+  var state = this._readableState;
+  var nOrig = n;
+  if (n !== 0) state.emittedReadable = false;
+
+  // if we're doing read(0) to trigger a readable event, but we
+  // already have a bunch of data in the buffer, then just trigger
+  // the 'readable' event and move on.
+  if (n === 0 && state.needReadable && ((state.highWaterMark !== 0 ? state.length >= state.highWaterMark : state.length > 0) || state.ended)) {
+    debug('read: emitReadable', state.length, state.ended);
+    if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
+    return null;
+  }
+  n = howMuchToRead(n, state);
+
+  // if we've ended, and we're now clear, then finish it up.
+  if (n === 0 && state.ended) {
+    if (state.length === 0) endReadable(this);
+    return null;
+  }
+
+  // All the actual chunk generation logic needs to be
+  // *below* the call to _read.  The reason is that in certain
+  // synthetic stream cases, such as passthrough streams, _read
+  // may be a completely synchronous operation which may change
+  // the state of the read buffer, providing enough data when
+  // before there was *not* enough.
+  //
+  // So, the steps are:
+  // 1. Figure out what the state of things will be after we do
+  // a read from the buffer.
+  //
+  // 2. If that resulting state will trigger a _read, then call _read.
+  // Note that this may be asynchronous, or synchronous.  Yes, it is
+  // deeply ugly to write APIs this way, but that still doesn't mean
+  // that the Readable class should behave improperly, as streams are
+  // designed to be sync/async agnostic.
+  // Take note if the _read call is sync or async (ie, if the read call
+  // has returned yet), so that we know whether or not it's safe to emit
+  // 'readable' etc.
+  //
+  // 3. Actually pull the requested chunks out of the buffer and return.
+
+  // if we need a readable event, then we need to do some reading.
+  var doRead = state.needReadable;
+  debug('need readable', doRead);
+
+  // if we currently have less than the highWaterMark, then also read some
+  if (state.length === 0 || state.length - n < state.highWaterMark) {
+    doRead = true;
+    debug('length less than watermark', doRead);
+  }
+
+  // however, if we've ended, then there's no point, and if we're already
+  // reading, then it's unnecessary.
+  if (state.ended || state.reading) {
+    doRead = false;
+    debug('reading or ended', doRead);
+  } else if (doRead) {
+    debug('do read');
+    state.reading = true;
+    state.sync = true;
+    // if the length is currently zero, then we *need* a readable event.
+    if (state.length === 0) state.needReadable = true;
+    // call internal read method
+    this._read(state.highWaterMark);
+    state.sync = false;
+    // If _read pushed data synchronously, then `reading` will be false,
+    // and we need to re-evaluate how much data we can return to the user.
+    if (!state.reading) n = howMuchToRead(nOrig, state);
+  }
+  var ret;
+  if (n > 0) ret = fromList(n, state);else ret = null;
+  if (ret === null) {
+    state.needReadable = state.length <= state.highWaterMark;
+    n = 0;
+  } else {
+    state.length -= n;
+    state.awaitDrain = 0;
+  }
+  if (state.length === 0) {
+    // If we have nothing in the buffer, then we want to know
+    // as soon as we *do* get something into the buffer.
+    if (!state.ended) state.needReadable = true;
+
+    // If we tried to read() past the EOF, then emit end on the next tick.
+    if (nOrig !== n && state.ended) endReadable(this);
+  }
+  if (ret !== null) this.emit('data', ret);
+  return ret;
+};
+function onEofChunk(stream, state) {
+  debug('onEofChunk');
+  if (state.ended) return;
+  if (state.decoder) {
+    var chunk = state.decoder.end();
+    if (chunk && chunk.length) {
+      state.buffer.push(chunk);
+      state.length += state.objectMode ? 1 : chunk.length;
+    }
+  }
+  state.ended = true;
+  if (state.sync) {
+    // if we are sync, wait until next tick to emit the data.
+    // Otherwise we risk emitting data in the flow()
+    // the readable code triggers during a read() call
+    emitReadable(stream);
+  } else {
+    // emit 'readable' now to make sure it gets picked up.
+    state.needReadable = false;
+    if (!state.emittedReadable) {
+      state.emittedReadable = true;
+      emitReadable_(stream);
+    }
+  }
+}
+
+// Don't emit readable right away in sync mode, because this can trigger
+// another read() call => stack overflow.  This way, it might trigger
+// a nextTick recursion warning, but that's not so bad.
+function emitReadable(stream) {
+  var state = stream._readableState;
+  debug('emitReadable', state.needReadable, state.emittedReadable);
+  state.needReadable = false;
+  if (!state.emittedReadable) {
+    debug('emitReadable', state.flowing);
+    state.emittedReadable = true;
+    process.nextTick(emitReadable_, stream);
+  }
+}
+function emitReadable_(stream) {
+  var state = stream._readableState;
+  debug('emitReadable_', state.destroyed, state.length, state.ended);
+  if (!state.destroyed && (state.length || state.ended)) {
+    stream.emit('readable');
+    state.emittedReadable = false;
+  }
+
+  // The stream needs another readable event if
+  // 1. It is not flowing, as the flow mechanism will take
+  //    care of it.
+  // 2. It is not ended.
+  // 3. It is below the highWaterMark, so we can schedule
+  //    another readable later.
+  state.needReadable = !state.flowing && !state.ended && state.length <= state.highWaterMark;
+  flow(stream);
+}
+
+// at this point, the user has presumably seen the 'readable' event,
+// and called read() to consume some data.  that may have triggered
+// in turn another _read(n) call, in which case reading = true if
+// it's in progress.
+// However, if we're not ended, or reading, and the length < hwm,
+// then go ahead and try to read some more preemptively.
+function maybeReadMore(stream, state) {
+  if (!state.readingMore) {
+    state.readingMore = true;
+    process.nextTick(maybeReadMore_, stream, state);
+  }
+}
+function maybeReadMore_(stream, state) {
+  // Attempt to read more data if we should.
+  //
+  // The conditions for reading more data are (one of):
+  // - Not enough data buffered (state.length < state.highWaterMark). The loop
+  //   is responsible for filling the buffer with enough data if such data
+  //   is available. If highWaterMark is 0 and we are not in the flowing mode
+  //   we should _not_ attempt to buffer any extra data. We'll get more data
+  //   when the stream consumer calls read() instead.
+  // - No data in the buffer, and the stream is in flowing mode. In this mode
+  //   the loop below is responsible for ensuring read() is called. Failing to
+  //   call read here would abort the flow and there's no other mechanism for
+  //   continuing the flow if the stream consumer has just subscribed to the
+  //   'data' event.
+  //
+  // In addition to the above conditions to keep reading data, the following
+  // conditions prevent the data from being read:
+  // - The stream has ended (state.ended).
+  // - There is already a pending 'read' operation (state.reading). This is a
+  //   case where the the stream has called the implementation defined _read()
+  //   method, but they are processing the call asynchronously and have _not_
+  //   called push() with new data. In this case we skip performing more
+  //   read()s. The execution ends in this method again after the _read() ends
+  //   up calling push() with more data.
+  while (!state.reading && !state.ended && (state.length < state.highWaterMark || state.flowing && state.length === 0)) {
+    var len = state.length;
+    debug('maybeReadMore read 0');
+    stream.read(0);
+    if (len === state.length)
+      // didn't get any data, stop spinning.
+      break;
+  }
+  state.readingMore = false;
+}
+
+// abstract method.  to be overridden in specific implementation classes.
+// call cb(er, data) where data is <= n in length.
+// for virtual (non-string, non-buffer) streams, "length" is somewhat
+// arbitrary, and perhaps not very meaningful.
+Readable.prototype._read = function (n) {
+  errorOrDestroy(this, new ERR_METHOD_NOT_IMPLEMENTED('_read()'));
+};
+Readable.prototype.pipe = function (dest, pipeOpts) {
+  var src = this;
+  var state = this._readableState;
+  switch (state.pipesCount) {
+    case 0:
+      state.pipes = dest;
+      break;
+    case 1:
+      state.pipes = [state.pipes, dest];
+      break;
+    default:
+      state.pipes.push(dest);
+      break;
+  }
+  state.pipesCount += 1;
+  debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);
+  var doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr;
+  var endFn = doEnd ? onend : unpipe;
+  if (state.endEmitted) process.nextTick(endFn);else src.once('end', endFn);
+  dest.on('unpipe', onunpipe);
+  function onunpipe(readable, unpipeInfo) {
+    debug('onunpipe');
+    if (readable === src) {
+      if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
+        unpipeInfo.hasUnpiped = true;
+        cleanup();
+      }
+    }
+  }
+  function onend() {
+    debug('onend');
+    dest.end();
+  }
+
+  // when the dest drains, it reduces the awaitDrain counter
+  // on the source.  This would be more elegant with a .once()
+  // handler in flow(), but adding and removing repeatedly is
+  // too slow.
+  var ondrain = pipeOnDrain(src);
+  dest.on('drain', ondrain);
+  var cleanedUp = false;
+  function cleanup() {
+    debug('cleanup');
+    // cleanup event handlers once the pipe is broken
+    dest.removeListener('close', onclose);
+    dest.removeListener('finish', onfinish);
+    dest.removeListener('drain', ondrain);
+    dest.removeListener('error', onerror);
+    dest.removeListener('unpipe', onunpipe);
+    src.removeListener('end', onend);
+    src.removeListener('end', unpipe);
+    src.removeListener('data', ondata);
+    cleanedUp = true;
+
+    // if the reader is waiting for a drain event from this
+    // specific writer, then it would cause it to never start
+    // flowing again.
+    // So, if this is awaiting a drain, then we just call it now.
+    // If we don't know, then assume that we are waiting for one.
+    if (state.awaitDrain && (!dest._writableState || dest._writableState.needDrain)) ondrain();
+  }
+  src.on('data', ondata);
+  function ondata(chunk) {
+    debug('ondata');
+    var ret = dest.write(chunk);
+    debug('dest.write', ret);
+    if (ret === false) {
+      // If the user unpiped during `dest.write()`, it is possible
+      // to get stuck in a permanently paused state if that write
+      // also returned false.
+      // => Check whether `dest` is still a piping destination.
+      if ((state.pipesCount === 1 && state.pipes === dest || state.pipesCount > 1 && indexOf(state.pipes, dest) !== -1) && !cleanedUp) {
+        debug('false write response, pause', state.awaitDrain);
+        state.awaitDrain++;
+      }
+      src.pause();
+    }
+  }
+
+  // if the dest has an error, then stop piping into it.
+  // however, don't suppress the throwing behavior for this.
+  function onerror(er) {
+    debug('onerror', er);
+    unpipe();
+    dest.removeListener('error', onerror);
+    if (EElistenerCount(dest, 'error') === 0) errorOrDestroy(dest, er);
+  }
+
+  // Make sure our error handler is attached before userland ones.
+  prependListener(dest, 'error', onerror);
+
+  // Both close and finish should trigger unpipe, but only once.
+  function onclose() {
+    dest.removeListener('finish', onfinish);
+    unpipe();
+  }
+  dest.once('close', onclose);
+  function onfinish() {
+    debug('onfinish');
+    dest.removeListener('close', onclose);
+    unpipe();
+  }
+  dest.once('finish', onfinish);
+  function unpipe() {
+    debug('unpipe');
+    src.unpipe(dest);
+  }
+
+  // tell the dest that it's being piped to
+  dest.emit('pipe', src);
+
+  // start the flow if it hasn't been started already.
+  if (!state.flowing) {
+    debug('pipe resume');
+    src.resume();
+  }
+  return dest;
+};
+function pipeOnDrain(src) {
+  return function pipeOnDrainFunctionResult() {
+    var state = src._readableState;
+    debug('pipeOnDrain', state.awaitDrain);
+    if (state.awaitDrain) state.awaitDrain--;
+    if (state.awaitDrain === 0 && EElistenerCount(src, 'data')) {
+      state.flowing = true;
+      flow(src);
+    }
+  };
+}
+Readable.prototype.unpipe = function (dest) {
+  var state = this._readableState;
+  var unpipeInfo = {
+    hasUnpiped: false
+  };
+
+  // if we're not piping anywhere, then do nothing.
+  if (state.pipesCount === 0) return this;
+
+  // just one destination.  most common case.
+  if (state.pipesCount === 1) {
+    // passed in one, but it's not the right one.
+    if (dest && dest !== state.pipes) return this;
+    if (!dest) dest = state.pipes;
+
+    // got a match.
+    state.pipes = null;
+    state.pipesCount = 0;
+    state.flowing = false;
+    if (dest) dest.emit('unpipe', this, unpipeInfo);
+    return this;
+  }
+
+  // slow case. multiple pipe destinations.
+
+  if (!dest) {
+    // remove all.
+    var dests = state.pipes;
+    var len = state.pipesCount;
+    state.pipes = null;
+    state.pipesCount = 0;
+    state.flowing = false;
+    for (var i = 0; i < len; i++) dests[i].emit('unpipe', this, {
+      hasUnpiped: false
+    });
+    return this;
+  }
+
+  // try to find the right one.
+  var index = indexOf(state.pipes, dest);
+  if (index === -1) return this;
+  state.pipes.splice(index, 1);
+  state.pipesCount -= 1;
+  if (state.pipesCount === 1) state.pipes = state.pipes[0];
+  dest.emit('unpipe', this, unpipeInfo);
+  return this;
+};
+
+// set up data events if they are asked for
+// Ensure readable listeners eventually get something
+Readable.prototype.on = function (ev, fn) {
+  var res = Stream.prototype.on.call(this, ev, fn);
+  var state = this._readableState;
+  if (ev === 'data') {
+    // update readableListening so that resume() may be a no-op
+    // a few lines down. This is needed to support once('readable').
+    state.readableListening = this.listenerCount('readable') > 0;
+
+    // Try start flowing on next tick if stream isn't explicitly paused
+    if (state.flowing !== false) this.resume();
+  } else if (ev === 'readable') {
+    if (!state.endEmitted && !state.readableListening) {
+      state.readableListening = state.needReadable = true;
+      state.flowing = false;
+      state.emittedReadable = false;
+      debug('on readable', state.length, state.reading);
+      if (state.length) {
+        emitReadable(this);
+      } else if (!state.reading) {
+        process.nextTick(nReadingNextTick, this);
+      }
+    }
+  }
+  return res;
+};
+Readable.prototype.addListener = Readable.prototype.on;
+Readable.prototype.removeListener = function (ev, fn) {
+  var res = Stream.prototype.removeListener.call(this, ev, fn);
+  if (ev === 'readable') {
+    // We need to check if there is someone still listening to
+    // readable and reset the state. However this needs to happen
+    // after readable has been emitted but before I/O (nextTick) to
+    // support once('readable', fn) cycles. This means that calling
+    // resume within the same tick will have no
+    // effect.
+    process.nextTick(updateReadableListening, this);
+  }
+  return res;
+};
+Readable.prototype.removeAllListeners = function (ev) {
+  var res = Stream.prototype.removeAllListeners.apply(this, arguments);
+  if (ev === 'readable' || ev === undefined) {
+    // We need to check if there is someone still listening to
+    // readable and reset the state. However this needs to happen
+    // after readable has been emitted but before I/O (nextTick) to
+    // support once('readable', fn) cycles. This means that calling
+    // resume within the same tick will have no
+    // effect.
+    process.nextTick(updateReadableListening, this);
+  }
+  return res;
+};
+function updateReadableListening(self) {
+  var state = self._readableState;
+  state.readableListening = self.listenerCount('readable') > 0;
+  if (state.resumeScheduled && !state.paused) {
+    // flowing needs to be set to true now, otherwise
+    // the upcoming resume will not flow.
+    state.flowing = true;
+
+    // crude way to check if we should resume
+  } else if (self.listenerCount('data') > 0) {
+    self.resume();
+  }
+}
+function nReadingNextTick(self) {
+  debug('readable nexttick read 0');
+  self.read(0);
+}
+
+// pause() and resume() are remnants of the legacy readable stream API
+// If the user uses them, then switch into old mode.
+Readable.prototype.resume = function () {
+  var state = this._readableState;
+  if (!state.flowing) {
+    debug('resume');
+    // we flow only if there is no one listening
+    // for readable, but we still have to call
+    // resume()
+    state.flowing = !state.readableListening;
+    resume(this, state);
+  }
+  state.paused = false;
+  return this;
+};
+function resume(stream, state) {
+  if (!state.resumeScheduled) {
+    state.resumeScheduled = true;
+    process.nextTick(resume_, stream, state);
+  }
+}
+function resume_(stream, state) {
+  debug('resume', state.reading);
+  if (!state.reading) {
+    stream.read(0);
+  }
+  state.resumeScheduled = false;
+  stream.emit('resume');
+  flow(stream);
+  if (state.flowing && !state.reading) stream.read(0);
+}
+Readable.prototype.pause = function () {
+  debug('call pause flowing=%j', this._readableState.flowing);
+  if (this._readableState.flowing !== false) {
+    debug('pause');
+    this._readableState.flowing = false;
+    this.emit('pause');
+  }
+  this._readableState.paused = true;
+  return this;
+};
+function flow(stream) {
+  var state = stream._readableState;
+  debug('flow', state.flowing);
+  while (state.flowing && stream.read() !== null);
+}
+
+// wrap an old-style stream as the async data source.
+// This is *not* part of the readable stream interface.
+// It is an ugly unfortunate mess of history.
+Readable.prototype.wrap = function (stream) {
+  var _this = this;
+  var state = this._readableState;
+  var paused = false;
+  stream.on('end', function () {
+    debug('wrapped end');
+    if (state.decoder && !state.ended) {
+      var chunk = state.decoder.end();
+      if (chunk && chunk.length) _this.push(chunk);
+    }
+    _this.push(null);
+  });
+  stream.on('data', function (chunk) {
+    debug('wrapped data');
+    if (state.decoder) chunk = state.decoder.write(chunk);
+
+    // don't skip over falsy values in objectMode
+    if (state.objectMode && (chunk === null || chunk === undefined)) return;else if (!state.objectMode && (!chunk || !chunk.length)) return;
+    var ret = _this.push(chunk);
+    if (!ret) {
+      paused = true;
+      stream.pause();
+    }
+  });
+
+  // proxy all the other methods.
+  // important when wrapping filters and duplexes.
+  for (var i in stream) {
+    if (this[i] === undefined && typeof stream[i] === 'function') {
+      this[i] = function methodWrap(method) {
+        return function methodWrapReturnFunction() {
+          return stream[method].apply(stream, arguments);
+        };
+      }(i);
+    }
+  }
+
+  // proxy certain important events.
+  for (var n = 0; n < kProxyEvents.length; n++) {
+    stream.on(kProxyEvents[n], this.emit.bind(this, kProxyEvents[n]));
+  }
+
+  // when we try to consume some more bytes, simply unpause the
+  // underlying stream.
+  this._read = function (n) {
+    debug('wrapped _read', n);
+    if (paused) {
+      paused = false;
+      stream.resume();
+    }
+  };
+  return this;
+};
+if (typeof Symbol === 'function') {
+  Readable.prototype[Symbol.asyncIterator] = function () {
+    if (createReadableStreamAsyncIterator === undefined) {
+      createReadableStreamAsyncIterator = require('./internal/streams/async_iterator');
+    }
+    return createReadableStreamAsyncIterator(this);
+  };
+}
+Object.defineProperty(Readable.prototype, 'readableHighWaterMark', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._readableState.highWaterMark;
+  }
+});
+Object.defineProperty(Readable.prototype, 'readableBuffer', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._readableState && this._readableState.buffer;
+  }
+});
+Object.defineProperty(Readable.prototype, 'readableFlowing', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._readableState.flowing;
+  },
+  set: function set(state) {
+    if (this._readableState) {
+      this._readableState.flowing = state;
+    }
+  }
+});
+
+// exposed for testing purposes only.
+Readable._fromList = fromList;
+Object.defineProperty(Readable.prototype, 'readableLength', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._readableState.length;
+  }
+});
+
+// Pluck off n bytes from an array of buffers.
+// Length is the combined lengths of all the buffers in the list.
+// This function is designed to be inlinable, so please take care when making
+// changes to the function body.
+function fromList(n, state) {
+  // nothing buffered
+  if (state.length === 0) return null;
+  var ret;
+  if (state.objectMode) ret = state.buffer.shift();else if (!n || n >= state.length) {
+    // read it all, truncate the list
+    if (state.decoder) ret = state.buffer.join('');else if (state.buffer.length === 1) ret = state.buffer.first();else ret = state.buffer.concat(state.length);
+    state.buffer.clear();
+  } else {
+    // read part of list
+    ret = state.buffer.consume(n, state.decoder);
+  }
+  return ret;
+}
+function endReadable(stream) {
+  var state = stream._readableState;
+  debug('endReadable', state.endEmitted);
+  if (!state.endEmitted) {
+    state.ended = true;
+    process.nextTick(endReadableNT, state, stream);
+  }
+}
+function endReadableNT(state, stream) {
+  debug('endReadableNT', state.endEmitted, state.length);
+
+  // Check that we didn't get one last unshift.
+  if (!state.endEmitted && state.length === 0) {
+    state.endEmitted = true;
+    stream.readable = false;
+    stream.emit('end');
+    if (state.autoDestroy) {
+      // In case of duplex streams we need a way to detect
+      // if the writable side is ready for autoDestroy as well
+      var wState = stream._writableState;
+      if (!wState || wState.autoDestroy && wState.finished) {
+        stream.destroy();
+      }
+    }
+  }
+}
+if (typeof Symbol === 'function') {
+  Readable.from = function (iterable, opts) {
+    if (from === undefined) {
+      from = require('./internal/streams/from');
+    }
+    return from(Readable, iterable, opts);
+  };
+}
+function indexOf(xs, x) {
+  for (var i = 0, l = xs.length; i < l; i++) {
+    if (xs[i] === x) return i;
+  }
+  return -1;
+}
Index: frontend/node_modules/readable-stream/lib/_stream_transform.js
===================================================================
--- frontend/node_modules/readable-stream/lib/_stream_transform.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/_stream_transform.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,190 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// a transform stream is a readable/writable stream where you do
+// something with the data.  Sometimes it's called a "filter",
+// but that's not a great name for it, since that implies a thing where
+// some bits pass through, and others are simply ignored.  (That would
+// be a valid example of a transform, of course.)
+//
+// While the output is causally related to the input, it's not a
+// necessarily symmetric or synchronous transformation.  For example,
+// a zlib stream might take multiple plain-text writes(), and then
+// emit a single compressed chunk some time in the future.
+//
+// Here's how this works:
+//
+// The Transform stream has all the aspects of the readable and writable
+// stream classes.  When you write(chunk), that calls _write(chunk,cb)
+// internally, and returns false if there's a lot of pending writes
+// buffered up.  When you call read(), that calls _read(n) until
+// there's enough pending readable data buffered up.
+//
+// In a transform stream, the written data is placed in a buffer.  When
+// _read(n) is called, it transforms the queued up data, calling the
+// buffered _write cb's as it consumes chunks.  If consuming a single
+// written chunk would result in multiple output chunks, then the first
+// outputted bit calls the readcb, and subsequent chunks just go into
+// the read buffer, and will cause it to emit 'readable' if necessary.
+//
+// This way, back-pressure is actually determined by the reading side,
+// since _read has to be called to start processing a new chunk.  However,
+// a pathological inflate type of transform can cause excessive buffering
+// here.  For example, imagine a stream where every byte of input is
+// interpreted as an integer from 0-255, and then results in that many
+// bytes of output.  Writing the 4 bytes {ff,ff,ff,ff} would result in
+// 1kb of data being output.  In this case, you could write a very small
+// amount of input, and end up with a very large amount of output.  In
+// such a pathological inflating mechanism, there'd be no way to tell
+// the system to stop doing the transform.  A single 4MB write could
+// cause the system to run out of memory.
+//
+// However, even in such a pathological case, only a single written chunk
+// would be consumed, and then the rest would wait (un-transformed) until
+// the results of the previous transformed chunk were consumed.
+
+'use strict';
+
+module.exports = Transform;
+var _require$codes = require('../errors').codes,
+  ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
+  ERR_MULTIPLE_CALLBACK = _require$codes.ERR_MULTIPLE_CALLBACK,
+  ERR_TRANSFORM_ALREADY_TRANSFORMING = _require$codes.ERR_TRANSFORM_ALREADY_TRANSFORMING,
+  ERR_TRANSFORM_WITH_LENGTH_0 = _require$codes.ERR_TRANSFORM_WITH_LENGTH_0;
+var Duplex = require('./_stream_duplex');
+require('inherits')(Transform, Duplex);
+function afterTransform(er, data) {
+  var ts = this._transformState;
+  ts.transforming = false;
+  var cb = ts.writecb;
+  if (cb === null) {
+    return this.emit('error', new ERR_MULTIPLE_CALLBACK());
+  }
+  ts.writechunk = null;
+  ts.writecb = null;
+  if (data != null)
+    // single equals check for both `null` and `undefined`
+    this.push(data);
+  cb(er);
+  var rs = this._readableState;
+  rs.reading = false;
+  if (rs.needReadable || rs.length < rs.highWaterMark) {
+    this._read(rs.highWaterMark);
+  }
+}
+function Transform(options) {
+  if (!(this instanceof Transform)) return new Transform(options);
+  Duplex.call(this, options);
+  this._transformState = {
+    afterTransform: afterTransform.bind(this),
+    needTransform: false,
+    transforming: false,
+    writecb: null,
+    writechunk: null,
+    writeencoding: null
+  };
+
+  // start out asking for a readable event once data is transformed.
+  this._readableState.needReadable = true;
+
+  // we have implemented the _read method, and done the other things
+  // that Readable wants before the first _read call, so unset the
+  // sync guard flag.
+  this._readableState.sync = false;
+  if (options) {
+    if (typeof options.transform === 'function') this._transform = options.transform;
+    if (typeof options.flush === 'function') this._flush = options.flush;
+  }
+
+  // When the writable side finishes, then flush out anything remaining.
+  this.on('prefinish', prefinish);
+}
+function prefinish() {
+  var _this = this;
+  if (typeof this._flush === 'function' && !this._readableState.destroyed) {
+    this._flush(function (er, data) {
+      done(_this, er, data);
+    });
+  } else {
+    done(this, null, null);
+  }
+}
+Transform.prototype.push = function (chunk, encoding) {
+  this._transformState.needTransform = false;
+  return Duplex.prototype.push.call(this, chunk, encoding);
+};
+
+// This is the part where you do stuff!
+// override this function in implementation classes.
+// 'chunk' is an input chunk.
+//
+// Call `push(newChunk)` to pass along transformed output
+// to the readable side.  You may call 'push' zero or more times.
+//
+// Call `cb(err)` when you are done with this chunk.  If you pass
+// an error, then that'll put the hurt on the whole operation.  If you
+// never call cb(), then you'll never get another chunk.
+Transform.prototype._transform = function (chunk, encoding, cb) {
+  cb(new ERR_METHOD_NOT_IMPLEMENTED('_transform()'));
+};
+Transform.prototype._write = function (chunk, encoding, cb) {
+  var ts = this._transformState;
+  ts.writecb = cb;
+  ts.writechunk = chunk;
+  ts.writeencoding = encoding;
+  if (!ts.transforming) {
+    var rs = this._readableState;
+    if (ts.needTransform || rs.needReadable || rs.length < rs.highWaterMark) this._read(rs.highWaterMark);
+  }
+};
+
+// Doesn't matter what the args are here.
+// _transform does all the work.
+// That we got here means that the readable side wants more data.
+Transform.prototype._read = function (n) {
+  var ts = this._transformState;
+  if (ts.writechunk !== null && !ts.transforming) {
+    ts.transforming = true;
+    this._transform(ts.writechunk, ts.writeencoding, ts.afterTransform);
+  } else {
+    // mark that we need a transform, so that any data that comes in
+    // will get processed, now that we've asked for it.
+    ts.needTransform = true;
+  }
+};
+Transform.prototype._destroy = function (err, cb) {
+  Duplex.prototype._destroy.call(this, err, function (err2) {
+    cb(err2);
+  });
+};
+function done(stream, er, data) {
+  if (er) return stream.emit('error', er);
+  if (data != null)
+    // single equals check for both `null` and `undefined`
+    stream.push(data);
+
+  // TODO(BridgeAR): Write a test for these two error cases
+  // if there's nothing in the write buffer, then that means
+  // that nothing more will ever be provided
+  if (stream._writableState.length) throw new ERR_TRANSFORM_WITH_LENGTH_0();
+  if (stream._transformState.transforming) throw new ERR_TRANSFORM_ALREADY_TRANSFORMING();
+  return stream.push(null);
+}
Index: frontend/node_modules/readable-stream/lib/_stream_writable.js
===================================================================
--- frontend/node_modules/readable-stream/lib/_stream_writable.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/_stream_writable.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,641 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// A bit simpler than readable streams.
+// Implement an async ._write(chunk, encoding, cb), and it'll handle all
+// the drain event emission and buffering.
+
+'use strict';
+
+module.exports = Writable;
+
+/* <replacement> */
+function WriteReq(chunk, encoding, cb) {
+  this.chunk = chunk;
+  this.encoding = encoding;
+  this.callback = cb;
+  this.next = null;
+}
+
+// It seems a linked list but it is not
+// there will be only 2 of these for each stream
+function CorkedRequest(state) {
+  var _this = this;
+  this.next = null;
+  this.entry = null;
+  this.finish = function () {
+    onCorkedFinish(_this, state);
+  };
+}
+/* </replacement> */
+
+/*<replacement>*/
+var Duplex;
+/*</replacement>*/
+
+Writable.WritableState = WritableState;
+
+/*<replacement>*/
+var internalUtil = {
+  deprecate: require('util-deprecate')
+};
+/*</replacement>*/
+
+/*<replacement>*/
+var Stream = require('./internal/streams/stream');
+/*</replacement>*/
+
+var Buffer = require('buffer').Buffer;
+var OurUint8Array = (typeof global !== 'undefined' ? global : typeof window !== 'undefined' ? window : typeof self !== 'undefined' ? self : {}).Uint8Array || function () {};
+function _uint8ArrayToBuffer(chunk) {
+  return Buffer.from(chunk);
+}
+function _isUint8Array(obj) {
+  return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
+}
+var destroyImpl = require('./internal/streams/destroy');
+var _require = require('./internal/streams/state'),
+  getHighWaterMark = _require.getHighWaterMark;
+var _require$codes = require('../errors').codes,
+  ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
+  ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
+  ERR_MULTIPLE_CALLBACK = _require$codes.ERR_MULTIPLE_CALLBACK,
+  ERR_STREAM_CANNOT_PIPE = _require$codes.ERR_STREAM_CANNOT_PIPE,
+  ERR_STREAM_DESTROYED = _require$codes.ERR_STREAM_DESTROYED,
+  ERR_STREAM_NULL_VALUES = _require$codes.ERR_STREAM_NULL_VALUES,
+  ERR_STREAM_WRITE_AFTER_END = _require$codes.ERR_STREAM_WRITE_AFTER_END,
+  ERR_UNKNOWN_ENCODING = _require$codes.ERR_UNKNOWN_ENCODING;
+var errorOrDestroy = destroyImpl.errorOrDestroy;
+require('inherits')(Writable, Stream);
+function nop() {}
+function WritableState(options, stream, isDuplex) {
+  Duplex = Duplex || require('./_stream_duplex');
+  options = options || {};
+
+  // Duplex streams are both readable and writable, but share
+  // the same options object.
+  // However, some cases require setting options to different
+  // values for the readable and the writable sides of the duplex stream,
+  // e.g. options.readableObjectMode vs. options.writableObjectMode, etc.
+  if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex;
+
+  // object stream flag to indicate whether or not this stream
+  // contains buffers or objects.
+  this.objectMode = !!options.objectMode;
+  if (isDuplex) this.objectMode = this.objectMode || !!options.writableObjectMode;
+
+  // the point at which write() starts returning false
+  // Note: 0 is a valid value, means that we always return false if
+  // the entire buffer is not flushed immediately on write()
+  this.highWaterMark = getHighWaterMark(this, options, 'writableHighWaterMark', isDuplex);
+
+  // if _final has been called
+  this.finalCalled = false;
+
+  // drain event flag.
+  this.needDrain = false;
+  // at the start of calling end()
+  this.ending = false;
+  // when end() has been called, and returned
+  this.ended = false;
+  // when 'finish' is emitted
+  this.finished = false;
+
+  // has it been destroyed
+  this.destroyed = false;
+
+  // should we decode strings into buffers before passing to _write?
+  // this is here so that some node-core streams can optimize string
+  // handling at a lower level.
+  var noDecode = options.decodeStrings === false;
+  this.decodeStrings = !noDecode;
+
+  // Crypto is kind of old and crusty.  Historically, its default string
+  // encoding is 'binary' so we have to make this configurable.
+  // Everything else in the universe uses 'utf8', though.
+  this.defaultEncoding = options.defaultEncoding || 'utf8';
+
+  // not an actual buffer we keep track of, but a measurement
+  // of how much we're waiting to get pushed to some underlying
+  // socket or file.
+  this.length = 0;
+
+  // a flag to see when we're in the middle of a write.
+  this.writing = false;
+
+  // when true all writes will be buffered until .uncork() call
+  this.corked = 0;
+
+  // a flag to be able to tell if the onwrite cb is called immediately,
+  // or on a later tick.  We set this to true at first, because any
+  // actions that shouldn't happen until "later" should generally also
+  // not happen before the first write call.
+  this.sync = true;
+
+  // a flag to know if we're processing previously buffered items, which
+  // may call the _write() callback in the same tick, so that we don't
+  // end up in an overlapped onwrite situation.
+  this.bufferProcessing = false;
+
+  // the callback that's passed to _write(chunk,cb)
+  this.onwrite = function (er) {
+    onwrite(stream, er);
+  };
+
+  // the callback that the user supplies to write(chunk,encoding,cb)
+  this.writecb = null;
+
+  // the amount that is being written when _write is called.
+  this.writelen = 0;
+  this.bufferedRequest = null;
+  this.lastBufferedRequest = null;
+
+  // number of pending user-supplied write callbacks
+  // this must be 0 before 'finish' can be emitted
+  this.pendingcb = 0;
+
+  // emit prefinish if the only thing we're waiting for is _write cbs
+  // This is relevant for synchronous Transform streams
+  this.prefinished = false;
+
+  // True if the error was already emitted and should not be thrown again
+  this.errorEmitted = false;
+
+  // Should close be emitted on destroy. Defaults to true.
+  this.emitClose = options.emitClose !== false;
+
+  // Should .destroy() be called after 'finish' (and potentially 'end')
+  this.autoDestroy = !!options.autoDestroy;
+
+  // count buffered requests
+  this.bufferedRequestCount = 0;
+
+  // allocate the first CorkedRequest, there is always
+  // one allocated and free to use, and we maintain at most two
+  this.corkedRequestsFree = new CorkedRequest(this);
+}
+WritableState.prototype.getBuffer = function getBuffer() {
+  var current = this.bufferedRequest;
+  var out = [];
+  while (current) {
+    out.push(current);
+    current = current.next;
+  }
+  return out;
+};
+(function () {
+  try {
+    Object.defineProperty(WritableState.prototype, 'buffer', {
+      get: internalUtil.deprecate(function writableStateBufferGetter() {
+        return this.getBuffer();
+      }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.', 'DEP0003')
+    });
+  } catch (_) {}
+})();
+
+// Test _writableState for inheritance to account for Duplex streams,
+// whose prototype chain only points to Readable.
+var realHasInstance;
+if (typeof Symbol === 'function' && Symbol.hasInstance && typeof Function.prototype[Symbol.hasInstance] === 'function') {
+  realHasInstance = Function.prototype[Symbol.hasInstance];
+  Object.defineProperty(Writable, Symbol.hasInstance, {
+    value: function value(object) {
+      if (realHasInstance.call(this, object)) return true;
+      if (this !== Writable) return false;
+      return object && object._writableState instanceof WritableState;
+    }
+  });
+} else {
+  realHasInstance = function realHasInstance(object) {
+    return object instanceof this;
+  };
+}
+function Writable(options) {
+  Duplex = Duplex || require('./_stream_duplex');
+
+  // Writable ctor is applied to Duplexes, too.
+  // `realHasInstance` is necessary because using plain `instanceof`
+  // would return false, as no `_writableState` property is attached.
+
+  // Trying to use the custom `instanceof` for Writable here will also break the
+  // Node.js LazyTransform implementation, which has a non-trivial getter for
+  // `_writableState` that would lead to infinite recursion.
+
+  // Checking for a Stream.Duplex instance is faster here instead of inside
+  // the WritableState constructor, at least with V8 6.5
+  var isDuplex = this instanceof Duplex;
+  if (!isDuplex && !realHasInstance.call(Writable, this)) return new Writable(options);
+  this._writableState = new WritableState(options, this, isDuplex);
+
+  // legacy.
+  this.writable = true;
+  if (options) {
+    if (typeof options.write === 'function') this._write = options.write;
+    if (typeof options.writev === 'function') this._writev = options.writev;
+    if (typeof options.destroy === 'function') this._destroy = options.destroy;
+    if (typeof options.final === 'function') this._final = options.final;
+  }
+  Stream.call(this);
+}
+
+// Otherwise people can pipe Writable streams, which is just wrong.
+Writable.prototype.pipe = function () {
+  errorOrDestroy(this, new ERR_STREAM_CANNOT_PIPE());
+};
+function writeAfterEnd(stream, cb) {
+  var er = new ERR_STREAM_WRITE_AFTER_END();
+  // TODO: defer error events consistently everywhere, not just the cb
+  errorOrDestroy(stream, er);
+  process.nextTick(cb, er);
+}
+
+// Checks that a user-supplied chunk is valid, especially for the particular
+// mode the stream is in. Currently this means that `null` is never accepted
+// and undefined/non-string values are only allowed in object mode.
+function validChunk(stream, state, chunk, cb) {
+  var er;
+  if (chunk === null) {
+    er = new ERR_STREAM_NULL_VALUES();
+  } else if (typeof chunk !== 'string' && !state.objectMode) {
+    er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer'], chunk);
+  }
+  if (er) {
+    errorOrDestroy(stream, er);
+    process.nextTick(cb, er);
+    return false;
+  }
+  return true;
+}
+Writable.prototype.write = function (chunk, encoding, cb) {
+  var state = this._writableState;
+  var ret = false;
+  var isBuf = !state.objectMode && _isUint8Array(chunk);
+  if (isBuf && !Buffer.isBuffer(chunk)) {
+    chunk = _uint8ArrayToBuffer(chunk);
+  }
+  if (typeof encoding === 'function') {
+    cb = encoding;
+    encoding = null;
+  }
+  if (isBuf) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding;
+  if (typeof cb !== 'function') cb = nop;
+  if (state.ending) writeAfterEnd(this, cb);else if (isBuf || validChunk(this, state, chunk, cb)) {
+    state.pendingcb++;
+    ret = writeOrBuffer(this, state, isBuf, chunk, encoding, cb);
+  }
+  return ret;
+};
+Writable.prototype.cork = function () {
+  this._writableState.corked++;
+};
+Writable.prototype.uncork = function () {
+  var state = this._writableState;
+  if (state.corked) {
+    state.corked--;
+    if (!state.writing && !state.corked && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state);
+  }
+};
+Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) {
+  // node::ParseEncoding() requires lower case.
+  if (typeof encoding === 'string') encoding = encoding.toLowerCase();
+  if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new ERR_UNKNOWN_ENCODING(encoding);
+  this._writableState.defaultEncoding = encoding;
+  return this;
+};
+Object.defineProperty(Writable.prototype, 'writableBuffer', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._writableState && this._writableState.getBuffer();
+  }
+});
+function decodeChunk(state, chunk, encoding) {
+  if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') {
+    chunk = Buffer.from(chunk, encoding);
+  }
+  return chunk;
+}
+Object.defineProperty(Writable.prototype, 'writableHighWaterMark', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._writableState.highWaterMark;
+  }
+});
+
+// if we're already writing something, then just put this
+// in the queue, and wait our turn.  Otherwise, call _write
+// If we return false, then we need a drain event, so set that flag.
+function writeOrBuffer(stream, state, isBuf, chunk, encoding, cb) {
+  if (!isBuf) {
+    var newChunk = decodeChunk(state, chunk, encoding);
+    if (chunk !== newChunk) {
+      isBuf = true;
+      encoding = 'buffer';
+      chunk = newChunk;
+    }
+  }
+  var len = state.objectMode ? 1 : chunk.length;
+  state.length += len;
+  var ret = state.length < state.highWaterMark;
+  // we must ensure that previous needDrain will not be reset to false.
+  if (!ret) state.needDrain = true;
+  if (state.writing || state.corked) {
+    var last = state.lastBufferedRequest;
+    state.lastBufferedRequest = {
+      chunk: chunk,
+      encoding: encoding,
+      isBuf: isBuf,
+      callback: cb,
+      next: null
+    };
+    if (last) {
+      last.next = state.lastBufferedRequest;
+    } else {
+      state.bufferedRequest = state.lastBufferedRequest;
+    }
+    state.bufferedRequestCount += 1;
+  } else {
+    doWrite(stream, state, false, len, chunk, encoding, cb);
+  }
+  return ret;
+}
+function doWrite(stream, state, writev, len, chunk, encoding, cb) {
+  state.writelen = len;
+  state.writecb = cb;
+  state.writing = true;
+  state.sync = true;
+  if (state.destroyed) state.onwrite(new ERR_STREAM_DESTROYED('write'));else if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite);
+  state.sync = false;
+}
+function onwriteError(stream, state, sync, er, cb) {
+  --state.pendingcb;
+  if (sync) {
+    // defer the callback if we are being called synchronously
+    // to avoid piling up things on the stack
+    process.nextTick(cb, er);
+    // this can emit finish, and it will always happen
+    // after error
+    process.nextTick(finishMaybe, stream, state);
+    stream._writableState.errorEmitted = true;
+    errorOrDestroy(stream, er);
+  } else {
+    // the caller expect this to happen before if
+    // it is async
+    cb(er);
+    stream._writableState.errorEmitted = true;
+    errorOrDestroy(stream, er);
+    // this can emit finish, but finish must
+    // always follow error
+    finishMaybe(stream, state);
+  }
+}
+function onwriteStateUpdate(state) {
+  state.writing = false;
+  state.writecb = null;
+  state.length -= state.writelen;
+  state.writelen = 0;
+}
+function onwrite(stream, er) {
+  var state = stream._writableState;
+  var sync = state.sync;
+  var cb = state.writecb;
+  if (typeof cb !== 'function') throw new ERR_MULTIPLE_CALLBACK();
+  onwriteStateUpdate(state);
+  if (er) onwriteError(stream, state, sync, er, cb);else {
+    // Check if we're actually ready to finish, but don't emit yet
+    var finished = needFinish(state) || stream.destroyed;
+    if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) {
+      clearBuffer(stream, state);
+    }
+    if (sync) {
+      process.nextTick(afterWrite, stream, state, finished, cb);
+    } else {
+      afterWrite(stream, state, finished, cb);
+    }
+  }
+}
+function afterWrite(stream, state, finished, cb) {
+  if (!finished) onwriteDrain(stream, state);
+  state.pendingcb--;
+  cb();
+  finishMaybe(stream, state);
+}
+
+// Must force callback to be called on nextTick, so that we don't
+// emit 'drain' before the write() consumer gets the 'false' return
+// value, and has a chance to attach a 'drain' listener.
+function onwriteDrain(stream, state) {
+  if (state.length === 0 && state.needDrain) {
+    state.needDrain = false;
+    stream.emit('drain');
+  }
+}
+
+// if there's something in the buffer waiting, then process it
+function clearBuffer(stream, state) {
+  state.bufferProcessing = true;
+  var entry = state.bufferedRequest;
+  if (stream._writev && entry && entry.next) {
+    // Fast case, write everything using _writev()
+    var l = state.bufferedRequestCount;
+    var buffer = new Array(l);
+    var holder = state.corkedRequestsFree;
+    holder.entry = entry;
+    var count = 0;
+    var allBuffers = true;
+    while (entry) {
+      buffer[count] = entry;
+      if (!entry.isBuf) allBuffers = false;
+      entry = entry.next;
+      count += 1;
+    }
+    buffer.allBuffers = allBuffers;
+    doWrite(stream, state, true, state.length, buffer, '', holder.finish);
+
+    // doWrite is almost always async, defer these to save a bit of time
+    // as the hot path ends with doWrite
+    state.pendingcb++;
+    state.lastBufferedRequest = null;
+    if (holder.next) {
+      state.corkedRequestsFree = holder.next;
+      holder.next = null;
+    } else {
+      state.corkedRequestsFree = new CorkedRequest(state);
+    }
+    state.bufferedRequestCount = 0;
+  } else {
+    // Slow case, write chunks one-by-one
+    while (entry) {
+      var chunk = entry.chunk;
+      var encoding = entry.encoding;
+      var cb = entry.callback;
+      var len = state.objectMode ? 1 : chunk.length;
+      doWrite(stream, state, false, len, chunk, encoding, cb);
+      entry = entry.next;
+      state.bufferedRequestCount--;
+      // if we didn't call the onwrite immediately, then
+      // it means that we need to wait until it does.
+      // also, that means that the chunk and cb are currently
+      // being processed, so move the buffer counter past them.
+      if (state.writing) {
+        break;
+      }
+    }
+    if (entry === null) state.lastBufferedRequest = null;
+  }
+  state.bufferedRequest = entry;
+  state.bufferProcessing = false;
+}
+Writable.prototype._write = function (chunk, encoding, cb) {
+  cb(new ERR_METHOD_NOT_IMPLEMENTED('_write()'));
+};
+Writable.prototype._writev = null;
+Writable.prototype.end = function (chunk, encoding, cb) {
+  var state = this._writableState;
+  if (typeof chunk === 'function') {
+    cb = chunk;
+    chunk = null;
+    encoding = null;
+  } else if (typeof encoding === 'function') {
+    cb = encoding;
+    encoding = null;
+  }
+  if (chunk !== null && chunk !== undefined) this.write(chunk, encoding);
+
+  // .end() fully uncorks
+  if (state.corked) {
+    state.corked = 1;
+    this.uncork();
+  }
+
+  // ignore unnecessary end() calls.
+  if (!state.ending) endWritable(this, state, cb);
+  return this;
+};
+Object.defineProperty(Writable.prototype, 'writableLength', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    return this._writableState.length;
+  }
+});
+function needFinish(state) {
+  return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing;
+}
+function callFinal(stream, state) {
+  stream._final(function (err) {
+    state.pendingcb--;
+    if (err) {
+      errorOrDestroy(stream, err);
+    }
+    state.prefinished = true;
+    stream.emit('prefinish');
+    finishMaybe(stream, state);
+  });
+}
+function prefinish(stream, state) {
+  if (!state.prefinished && !state.finalCalled) {
+    if (typeof stream._final === 'function' && !state.destroyed) {
+      state.pendingcb++;
+      state.finalCalled = true;
+      process.nextTick(callFinal, stream, state);
+    } else {
+      state.prefinished = true;
+      stream.emit('prefinish');
+    }
+  }
+}
+function finishMaybe(stream, state) {
+  var need = needFinish(state);
+  if (need) {
+    prefinish(stream, state);
+    if (state.pendingcb === 0) {
+      state.finished = true;
+      stream.emit('finish');
+      if (state.autoDestroy) {
+        // In case of duplex streams we need a way to detect
+        // if the readable side is ready for autoDestroy as well
+        var rState = stream._readableState;
+        if (!rState || rState.autoDestroy && rState.endEmitted) {
+          stream.destroy();
+        }
+      }
+    }
+  }
+  return need;
+}
+function endWritable(stream, state, cb) {
+  state.ending = true;
+  finishMaybe(stream, state);
+  if (cb) {
+    if (state.finished) process.nextTick(cb);else stream.once('finish', cb);
+  }
+  state.ended = true;
+  stream.writable = false;
+}
+function onCorkedFinish(corkReq, state, err) {
+  var entry = corkReq.entry;
+  corkReq.entry = null;
+  while (entry) {
+    var cb = entry.callback;
+    state.pendingcb--;
+    cb(err);
+    entry = entry.next;
+  }
+
+  // reuse the free corkReq.
+  state.corkedRequestsFree.next = corkReq;
+}
+Object.defineProperty(Writable.prototype, 'destroyed', {
+  // making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get: function get() {
+    if (this._writableState === undefined) {
+      return false;
+    }
+    return this._writableState.destroyed;
+  },
+  set: function set(value) {
+    // we ignore the value if the stream
+    // has not been initialized yet
+    if (!this._writableState) {
+      return;
+    }
+
+    // backward compatibility, the user is explicitly
+    // managing destroyed
+    this._writableState.destroyed = value;
+  }
+});
+Writable.prototype.destroy = destroyImpl.destroy;
+Writable.prototype._undestroy = destroyImpl.undestroy;
+Writable.prototype._destroy = function (err, cb) {
+  cb(err);
+};
Index: frontend/node_modules/readable-stream/lib/internal/streams/async_iterator.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/async_iterator.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/async_iterator.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,180 @@
+'use strict';
+
+var _Object$setPrototypeO;
+function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
+function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
+function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
+var finished = require('./end-of-stream');
+var kLastResolve = Symbol('lastResolve');
+var kLastReject = Symbol('lastReject');
+var kError = Symbol('error');
+var kEnded = Symbol('ended');
+var kLastPromise = Symbol('lastPromise');
+var kHandlePromise = Symbol('handlePromise');
+var kStream = Symbol('stream');
+function createIterResult(value, done) {
+  return {
+    value: value,
+    done: done
+  };
+}
+function readAndResolve(iter) {
+  var resolve = iter[kLastResolve];
+  if (resolve !== null) {
+    var data = iter[kStream].read();
+    // we defer if data is null
+    // we can be expecting either 'end' or
+    // 'error'
+    if (data !== null) {
+      iter[kLastPromise] = null;
+      iter[kLastResolve] = null;
+      iter[kLastReject] = null;
+      resolve(createIterResult(data, false));
+    }
+  }
+}
+function onReadable(iter) {
+  // we wait for the next tick, because it might
+  // emit an error with process.nextTick
+  process.nextTick(readAndResolve, iter);
+}
+function wrapForNext(lastPromise, iter) {
+  return function (resolve, reject) {
+    lastPromise.then(function () {
+      if (iter[kEnded]) {
+        resolve(createIterResult(undefined, true));
+        return;
+      }
+      iter[kHandlePromise](resolve, reject);
+    }, reject);
+  };
+}
+var AsyncIteratorPrototype = Object.getPrototypeOf(function () {});
+var ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf((_Object$setPrototypeO = {
+  get stream() {
+    return this[kStream];
+  },
+  next: function next() {
+    var _this = this;
+    // if we have detected an error in the meanwhile
+    // reject straight away
+    var error = this[kError];
+    if (error !== null) {
+      return Promise.reject(error);
+    }
+    if (this[kEnded]) {
+      return Promise.resolve(createIterResult(undefined, true));
+    }
+    if (this[kStream].destroyed) {
+      // We need to defer via nextTick because if .destroy(err) is
+      // called, the error will be emitted via nextTick, and
+      // we cannot guarantee that there is no error lingering around
+      // waiting to be emitted.
+      return new Promise(function (resolve, reject) {
+        process.nextTick(function () {
+          if (_this[kError]) {
+            reject(_this[kError]);
+          } else {
+            resolve(createIterResult(undefined, true));
+          }
+        });
+      });
+    }
+
+    // if we have multiple next() calls
+    // we will wait for the previous Promise to finish
+    // this logic is optimized to support for await loops,
+    // where next() is only called once at a time
+    var lastPromise = this[kLastPromise];
+    var promise;
+    if (lastPromise) {
+      promise = new Promise(wrapForNext(lastPromise, this));
+    } else {
+      // fast path needed to support multiple this.push()
+      // without triggering the next() queue
+      var data = this[kStream].read();
+      if (data !== null) {
+        return Promise.resolve(createIterResult(data, false));
+      }
+      promise = new Promise(this[kHandlePromise]);
+    }
+    this[kLastPromise] = promise;
+    return promise;
+  }
+}, _defineProperty(_Object$setPrototypeO, Symbol.asyncIterator, function () {
+  return this;
+}), _defineProperty(_Object$setPrototypeO, "return", function _return() {
+  var _this2 = this;
+  // destroy(err, cb) is a private API
+  // we can guarantee we have that here, because we control the
+  // Readable class this is attached to
+  return new Promise(function (resolve, reject) {
+    _this2[kStream].destroy(null, function (err) {
+      if (err) {
+        reject(err);
+        return;
+      }
+      resolve(createIterResult(undefined, true));
+    });
+  });
+}), _Object$setPrototypeO), AsyncIteratorPrototype);
+var createReadableStreamAsyncIterator = function createReadableStreamAsyncIterator(stream) {
+  var _Object$create;
+  var iterator = Object.create(ReadableStreamAsyncIteratorPrototype, (_Object$create = {}, _defineProperty(_Object$create, kStream, {
+    value: stream,
+    writable: true
+  }), _defineProperty(_Object$create, kLastResolve, {
+    value: null,
+    writable: true
+  }), _defineProperty(_Object$create, kLastReject, {
+    value: null,
+    writable: true
+  }), _defineProperty(_Object$create, kError, {
+    value: null,
+    writable: true
+  }), _defineProperty(_Object$create, kEnded, {
+    value: stream._readableState.endEmitted,
+    writable: true
+  }), _defineProperty(_Object$create, kHandlePromise, {
+    value: function value(resolve, reject) {
+      var data = iterator[kStream].read();
+      if (data) {
+        iterator[kLastPromise] = null;
+        iterator[kLastResolve] = null;
+        iterator[kLastReject] = null;
+        resolve(createIterResult(data, false));
+      } else {
+        iterator[kLastResolve] = resolve;
+        iterator[kLastReject] = reject;
+      }
+    },
+    writable: true
+  }), _Object$create));
+  iterator[kLastPromise] = null;
+  finished(stream, function (err) {
+    if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
+      var reject = iterator[kLastReject];
+      // reject if we are waiting for data in the Promise
+      // returned by next() and store the error
+      if (reject !== null) {
+        iterator[kLastPromise] = null;
+        iterator[kLastResolve] = null;
+        iterator[kLastReject] = null;
+        reject(err);
+      }
+      iterator[kError] = err;
+      return;
+    }
+    var resolve = iterator[kLastResolve];
+    if (resolve !== null) {
+      iterator[kLastPromise] = null;
+      iterator[kLastResolve] = null;
+      iterator[kLastReject] = null;
+      resolve(createIterResult(undefined, true));
+    }
+    iterator[kEnded] = true;
+  });
+  stream.on('readable', onReadable.bind(null, iterator));
+  return iterator;
+};
+module.exports = createReadableStreamAsyncIterator;
Index: frontend/node_modules/readable-stream/lib/internal/streams/buffer_list.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/buffer_list.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/buffer_list.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,183 @@
+'use strict';
+
+function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }
+function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }
+function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
+function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, _toPropertyKey(descriptor.key), descriptor); } }
+function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }
+function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
+function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
+var _require = require('buffer'),
+  Buffer = _require.Buffer;
+var _require2 = require('util'),
+  inspect = _require2.inspect;
+var custom = inspect && inspect.custom || 'inspect';
+function copyBuffer(src, target, offset) {
+  Buffer.prototype.copy.call(src, target, offset);
+}
+module.exports = /*#__PURE__*/function () {
+  function BufferList() {
+    _classCallCheck(this, BufferList);
+    this.head = null;
+    this.tail = null;
+    this.length = 0;
+  }
+  _createClass(BufferList, [{
+    key: "push",
+    value: function push(v) {
+      var entry = {
+        data: v,
+        next: null
+      };
+      if (this.length > 0) this.tail.next = entry;else this.head = entry;
+      this.tail = entry;
+      ++this.length;
+    }
+  }, {
+    key: "unshift",
+    value: function unshift(v) {
+      var entry = {
+        data: v,
+        next: this.head
+      };
+      if (this.length === 0) this.tail = entry;
+      this.head = entry;
+      ++this.length;
+    }
+  }, {
+    key: "shift",
+    value: function shift() {
+      if (this.length === 0) return;
+      var ret = this.head.data;
+      if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
+      --this.length;
+      return ret;
+    }
+  }, {
+    key: "clear",
+    value: function clear() {
+      this.head = this.tail = null;
+      this.length = 0;
+    }
+  }, {
+    key: "join",
+    value: function join(s) {
+      if (this.length === 0) return '';
+      var p = this.head;
+      var ret = '' + p.data;
+      while (p = p.next) ret += s + p.data;
+      return ret;
+    }
+  }, {
+    key: "concat",
+    value: function concat(n) {
+      if (this.length === 0) return Buffer.alloc(0);
+      var ret = Buffer.allocUnsafe(n >>> 0);
+      var p = this.head;
+      var i = 0;
+      while (p) {
+        copyBuffer(p.data, ret, i);
+        i += p.data.length;
+        p = p.next;
+      }
+      return ret;
+    }
+
+    // Consumes a specified amount of bytes or characters from the buffered data.
+  }, {
+    key: "consume",
+    value: function consume(n, hasStrings) {
+      var ret;
+      if (n < this.head.data.length) {
+        // `slice` is the same for buffers and strings.
+        ret = this.head.data.slice(0, n);
+        this.head.data = this.head.data.slice(n);
+      } else if (n === this.head.data.length) {
+        // First chunk is a perfect match.
+        ret = this.shift();
+      } else {
+        // Result spans more than one buffer.
+        ret = hasStrings ? this._getString(n) : this._getBuffer(n);
+      }
+      return ret;
+    }
+  }, {
+    key: "first",
+    value: function first() {
+      return this.head.data;
+    }
+
+    // Consumes a specified amount of characters from the buffered data.
+  }, {
+    key: "_getString",
+    value: function _getString(n) {
+      var p = this.head;
+      var c = 1;
+      var ret = p.data;
+      n -= ret.length;
+      while (p = p.next) {
+        var str = p.data;
+        var nb = n > str.length ? str.length : n;
+        if (nb === str.length) ret += str;else ret += str.slice(0, n);
+        n -= nb;
+        if (n === 0) {
+          if (nb === str.length) {
+            ++c;
+            if (p.next) this.head = p.next;else this.head = this.tail = null;
+          } else {
+            this.head = p;
+            p.data = str.slice(nb);
+          }
+          break;
+        }
+        ++c;
+      }
+      this.length -= c;
+      return ret;
+    }
+
+    // Consumes a specified amount of bytes from the buffered data.
+  }, {
+    key: "_getBuffer",
+    value: function _getBuffer(n) {
+      var ret = Buffer.allocUnsafe(n);
+      var p = this.head;
+      var c = 1;
+      p.data.copy(ret);
+      n -= p.data.length;
+      while (p = p.next) {
+        var buf = p.data;
+        var nb = n > buf.length ? buf.length : n;
+        buf.copy(ret, ret.length - n, 0, nb);
+        n -= nb;
+        if (n === 0) {
+          if (nb === buf.length) {
+            ++c;
+            if (p.next) this.head = p.next;else this.head = this.tail = null;
+          } else {
+            this.head = p;
+            p.data = buf.slice(nb);
+          }
+          break;
+        }
+        ++c;
+      }
+      this.length -= c;
+      return ret;
+    }
+
+    // Make sure the linked list only shows the minimal necessary information.
+  }, {
+    key: custom,
+    value: function value(_, options) {
+      return inspect(this, _objectSpread(_objectSpread({}, options), {}, {
+        // Only inspect one level.
+        depth: 0,
+        // It should not recurse.
+        customInspect: false
+      }));
+    }
+  }]);
+  return BufferList;
+}();
Index: frontend/node_modules/readable-stream/lib/internal/streams/destroy.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/destroy.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/destroy.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,96 @@
+'use strict';
+
+// undocumented cb() API, needed for core, not for public API
+function destroy(err, cb) {
+  var _this = this;
+  var readableDestroyed = this._readableState && this._readableState.destroyed;
+  var writableDestroyed = this._writableState && this._writableState.destroyed;
+  if (readableDestroyed || writableDestroyed) {
+    if (cb) {
+      cb(err);
+    } else if (err) {
+      if (!this._writableState) {
+        process.nextTick(emitErrorNT, this, err);
+      } else if (!this._writableState.errorEmitted) {
+        this._writableState.errorEmitted = true;
+        process.nextTick(emitErrorNT, this, err);
+      }
+    }
+    return this;
+  }
+
+  // we set destroyed to true before firing error callbacks in order
+  // to make it re-entrance safe in case destroy() is called within callbacks
+
+  if (this._readableState) {
+    this._readableState.destroyed = true;
+  }
+
+  // if this is a duplex stream mark the writable part as destroyed as well
+  if (this._writableState) {
+    this._writableState.destroyed = true;
+  }
+  this._destroy(err || null, function (err) {
+    if (!cb && err) {
+      if (!_this._writableState) {
+        process.nextTick(emitErrorAndCloseNT, _this, err);
+      } else if (!_this._writableState.errorEmitted) {
+        _this._writableState.errorEmitted = true;
+        process.nextTick(emitErrorAndCloseNT, _this, err);
+      } else {
+        process.nextTick(emitCloseNT, _this);
+      }
+    } else if (cb) {
+      process.nextTick(emitCloseNT, _this);
+      cb(err);
+    } else {
+      process.nextTick(emitCloseNT, _this);
+    }
+  });
+  return this;
+}
+function emitErrorAndCloseNT(self, err) {
+  emitErrorNT(self, err);
+  emitCloseNT(self);
+}
+function emitCloseNT(self) {
+  if (self._writableState && !self._writableState.emitClose) return;
+  if (self._readableState && !self._readableState.emitClose) return;
+  self.emit('close');
+}
+function undestroy() {
+  if (this._readableState) {
+    this._readableState.destroyed = false;
+    this._readableState.reading = false;
+    this._readableState.ended = false;
+    this._readableState.endEmitted = false;
+  }
+  if (this._writableState) {
+    this._writableState.destroyed = false;
+    this._writableState.ended = false;
+    this._writableState.ending = false;
+    this._writableState.finalCalled = false;
+    this._writableState.prefinished = false;
+    this._writableState.finished = false;
+    this._writableState.errorEmitted = false;
+  }
+}
+function emitErrorNT(self, err) {
+  self.emit('error', err);
+}
+function errorOrDestroy(stream, err) {
+  // We have tests that rely on errors being emitted
+  // in the same tick, so changing this is semver major.
+  // For now when you opt-in to autoDestroy we allow
+  // the error to be emitted nextTick. In a future
+  // semver major update we should change the default to this.
+
+  var rState = stream._readableState;
+  var wState = stream._writableState;
+  if (rState && rState.autoDestroy || wState && wState.autoDestroy) stream.destroy(err);else stream.emit('error', err);
+}
+module.exports = {
+  destroy: destroy,
+  undestroy: undestroy,
+  errorOrDestroy: errorOrDestroy
+};
Index: frontend/node_modules/readable-stream/lib/internal/streams/end-of-stream.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/end-of-stream.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/end-of-stream.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,86 @@
+// Ported from https://github.com/mafintosh/end-of-stream with
+// permission from the author, Mathias Buus (@mafintosh).
+
+'use strict';
+
+var ERR_STREAM_PREMATURE_CLOSE = require('../../../errors').codes.ERR_STREAM_PREMATURE_CLOSE;
+function once(callback) {
+  var called = false;
+  return function () {
+    if (called) return;
+    called = true;
+    for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
+      args[_key] = arguments[_key];
+    }
+    callback.apply(this, args);
+  };
+}
+function noop() {}
+function isRequest(stream) {
+  return stream.setHeader && typeof stream.abort === 'function';
+}
+function eos(stream, opts, callback) {
+  if (typeof opts === 'function') return eos(stream, null, opts);
+  if (!opts) opts = {};
+  callback = once(callback || noop);
+  var readable = opts.readable || opts.readable !== false && stream.readable;
+  var writable = opts.writable || opts.writable !== false && stream.writable;
+  var onlegacyfinish = function onlegacyfinish() {
+    if (!stream.writable) onfinish();
+  };
+  var writableEnded = stream._writableState && stream._writableState.finished;
+  var onfinish = function onfinish() {
+    writable = false;
+    writableEnded = true;
+    if (!readable) callback.call(stream);
+  };
+  var readableEnded = stream._readableState && stream._readableState.endEmitted;
+  var onend = function onend() {
+    readable = false;
+    readableEnded = true;
+    if (!writable) callback.call(stream);
+  };
+  var onerror = function onerror(err) {
+    callback.call(stream, err);
+  };
+  var onclose = function onclose() {
+    var err;
+    if (readable && !readableEnded) {
+      if (!stream._readableState || !stream._readableState.ended) err = new ERR_STREAM_PREMATURE_CLOSE();
+      return callback.call(stream, err);
+    }
+    if (writable && !writableEnded) {
+      if (!stream._writableState || !stream._writableState.ended) err = new ERR_STREAM_PREMATURE_CLOSE();
+      return callback.call(stream, err);
+    }
+  };
+  var onrequest = function onrequest() {
+    stream.req.on('finish', onfinish);
+  };
+  if (isRequest(stream)) {
+    stream.on('complete', onfinish);
+    stream.on('abort', onclose);
+    if (stream.req) onrequest();else stream.on('request', onrequest);
+  } else if (writable && !stream._writableState) {
+    // legacy streams
+    stream.on('end', onlegacyfinish);
+    stream.on('close', onlegacyfinish);
+  }
+  stream.on('end', onend);
+  stream.on('finish', onfinish);
+  if (opts.error !== false) stream.on('error', onerror);
+  stream.on('close', onclose);
+  return function () {
+    stream.removeListener('complete', onfinish);
+    stream.removeListener('abort', onclose);
+    stream.removeListener('request', onrequest);
+    if (stream.req) stream.req.removeListener('finish', onfinish);
+    stream.removeListener('end', onlegacyfinish);
+    stream.removeListener('close', onlegacyfinish);
+    stream.removeListener('finish', onfinish);
+    stream.removeListener('end', onend);
+    stream.removeListener('error', onerror);
+    stream.removeListener('close', onclose);
+  };
+}
+module.exports = eos;
Index: frontend/node_modules/readable-stream/lib/internal/streams/from-browser.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/from-browser.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/from-browser.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,3 @@
+module.exports = function () {
+  throw new Error('Readable.from is not available in the browser')
+};
Index: frontend/node_modules/readable-stream/lib/internal/streams/from.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/from.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/from.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,52 @@
+'use strict';
+
+function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { Promise.resolve(value).then(_next, _throw); } }
+function _asyncToGenerator(fn) { return function () { var self = this, args = arguments; return new Promise(function (resolve, reject) { var gen = fn.apply(self, args); function _next(value) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value); } function _throw(err) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err); } _next(undefined); }); }; }
+function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }
+function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }
+function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
+function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
+function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
+var ERR_INVALID_ARG_TYPE = require('../../../errors').codes.ERR_INVALID_ARG_TYPE;
+function from(Readable, iterable, opts) {
+  var iterator;
+  if (iterable && typeof iterable.next === 'function') {
+    iterator = iterable;
+  } else if (iterable && iterable[Symbol.asyncIterator]) iterator = iterable[Symbol.asyncIterator]();else if (iterable && iterable[Symbol.iterator]) iterator = iterable[Symbol.iterator]();else throw new ERR_INVALID_ARG_TYPE('iterable', ['Iterable'], iterable);
+  var readable = new Readable(_objectSpread({
+    objectMode: true
+  }, opts));
+  // Reading boolean to protect against _read
+  // being called before last iteration completion.
+  var reading = false;
+  readable._read = function () {
+    if (!reading) {
+      reading = true;
+      next();
+    }
+  };
+  function next() {
+    return _next2.apply(this, arguments);
+  }
+  function _next2() {
+    _next2 = _asyncToGenerator(function* () {
+      try {
+        var _yield$iterator$next = yield iterator.next(),
+          value = _yield$iterator$next.value,
+          done = _yield$iterator$next.done;
+        if (done) {
+          readable.push(null);
+        } else if (readable.push(yield value)) {
+          next();
+        } else {
+          reading = false;
+        }
+      } catch (err) {
+        readable.destroy(err);
+      }
+    });
+    return _next2.apply(this, arguments);
+  }
+  return readable;
+}
+module.exports = from;
Index: frontend/node_modules/readable-stream/lib/internal/streams/pipeline.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/pipeline.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/pipeline.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,86 @@
+// Ported from https://github.com/mafintosh/pump with
+// permission from the author, Mathias Buus (@mafintosh).
+
+'use strict';
+
+var eos;
+function once(callback) {
+  var called = false;
+  return function () {
+    if (called) return;
+    called = true;
+    callback.apply(void 0, arguments);
+  };
+}
+var _require$codes = require('../../../errors').codes,
+  ERR_MISSING_ARGS = _require$codes.ERR_MISSING_ARGS,
+  ERR_STREAM_DESTROYED = _require$codes.ERR_STREAM_DESTROYED;
+function noop(err) {
+  // Rethrow the error if it exists to avoid swallowing it
+  if (err) throw err;
+}
+function isRequest(stream) {
+  return stream.setHeader && typeof stream.abort === 'function';
+}
+function destroyer(stream, reading, writing, callback) {
+  callback = once(callback);
+  var closed = false;
+  stream.on('close', function () {
+    closed = true;
+  });
+  if (eos === undefined) eos = require('./end-of-stream');
+  eos(stream, {
+    readable: reading,
+    writable: writing
+  }, function (err) {
+    if (err) return callback(err);
+    closed = true;
+    callback();
+  });
+  var destroyed = false;
+  return function (err) {
+    if (closed) return;
+    if (destroyed) return;
+    destroyed = true;
+
+    // request.destroy just do .end - .abort is what we want
+    if (isRequest(stream)) return stream.abort();
+    if (typeof stream.destroy === 'function') return stream.destroy();
+    callback(err || new ERR_STREAM_DESTROYED('pipe'));
+  };
+}
+function call(fn) {
+  fn();
+}
+function pipe(from, to) {
+  return from.pipe(to);
+}
+function popCallback(streams) {
+  if (!streams.length) return noop;
+  if (typeof streams[streams.length - 1] !== 'function') return noop;
+  return streams.pop();
+}
+function pipeline() {
+  for (var _len = arguments.length, streams = new Array(_len), _key = 0; _key < _len; _key++) {
+    streams[_key] = arguments[_key];
+  }
+  var callback = popCallback(streams);
+  if (Array.isArray(streams[0])) streams = streams[0];
+  if (streams.length < 2) {
+    throw new ERR_MISSING_ARGS('streams');
+  }
+  var error;
+  var destroys = streams.map(function (stream, i) {
+    var reading = i < streams.length - 1;
+    var writing = i > 0;
+    return destroyer(stream, reading, writing, function (err) {
+      if (!error) error = err;
+      if (err) destroys.forEach(call);
+      if (reading) return;
+      destroys.forEach(call);
+      callback(error);
+    });
+  });
+  return streams.reduce(pipe);
+}
+module.exports = pipeline;
Index: frontend/node_modules/readable-stream/lib/internal/streams/state.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/state.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/state.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,22 @@
+'use strict';
+
+var ERR_INVALID_OPT_VALUE = require('../../../errors').codes.ERR_INVALID_OPT_VALUE;
+function highWaterMarkFrom(options, isDuplex, duplexKey) {
+  return options.highWaterMark != null ? options.highWaterMark : isDuplex ? options[duplexKey] : null;
+}
+function getHighWaterMark(state, options, duplexKey, isDuplex) {
+  var hwm = highWaterMarkFrom(options, isDuplex, duplexKey);
+  if (hwm != null) {
+    if (!(isFinite(hwm) && Math.floor(hwm) === hwm) || hwm < 0) {
+      var name = isDuplex ? duplexKey : 'highWaterMark';
+      throw new ERR_INVALID_OPT_VALUE(name, hwm);
+    }
+    return Math.floor(hwm);
+  }
+
+  // Default value
+  return state.objectMode ? 16 : 16 * 1024;
+}
+module.exports = {
+  getHighWaterMark: getHighWaterMark
+};
Index: frontend/node_modules/readable-stream/lib/internal/streams/stream-browser.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/stream-browser.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/stream-browser.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,1 @@
+module.exports = require('events').EventEmitter;
Index: frontend/node_modules/readable-stream/lib/internal/streams/stream.js
===================================================================
--- frontend/node_modules/readable-stream/lib/internal/streams/stream.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/readable-stream/lib/internal/streams/stream.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,1 @@
+module.exports = require('stream');
