Index: node_modules/internmap/src/index.js
===================================================================
--- node_modules/internmap/src/index.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/internmap/src/index.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,61 @@
+export class InternMap extends Map {
+  constructor(entries, key = keyof) {
+    super();
+    Object.defineProperties(this, {_intern: {value: new Map()}, _key: {value: key}});
+    if (entries != null) for (const [key, value] of entries) this.set(key, value);
+  }
+  get(key) {
+    return super.get(intern_get(this, key));
+  }
+  has(key) {
+    return super.has(intern_get(this, key));
+  }
+  set(key, value) {
+    return super.set(intern_set(this, key), value);
+  }
+  delete(key) {
+    return super.delete(intern_delete(this, key));
+  }
+}
+
+export class InternSet extends Set {
+  constructor(values, key = keyof) {
+    super();
+    Object.defineProperties(this, {_intern: {value: new Map()}, _key: {value: key}});
+    if (values != null) for (const value of values) this.add(value);
+  }
+  has(value) {
+    return super.has(intern_get(this, value));
+  }
+  add(value) {
+    return super.add(intern_set(this, value));
+  }
+  delete(value) {
+    return super.delete(intern_delete(this, value));
+  }
+}
+
+function intern_get({_intern, _key}, value) {
+  const key = _key(value);
+  return _intern.has(key) ? _intern.get(key) : value;
+}
+
+function intern_set({_intern, _key}, value) {
+  const key = _key(value);
+  if (_intern.has(key)) return _intern.get(key);
+  _intern.set(key, value);
+  return value;
+}
+
+function intern_delete({_intern, _key}, value) {
+  const key = _key(value);
+  if (_intern.has(key)) {
+    value = _intern.get(key);
+    _intern.delete(key);
+  }
+  return value;
+}
+
+function keyof(value) {
+  return value !== null && typeof value === "object" ? value.valueOf() : value;
+}