Index: node_modules/d3-hierarchy/dist/d3-hierarchy.js
===================================================================
--- node_modules/d3-hierarchy/dist/d3-hierarchy.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-hierarchy/dist/d3-hierarchy.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,1410 @@
+// https://d3js.org/d3-hierarchy/ v3.1.2 Copyright 2010-2021 Mike Bostock
+(function (global, factory) {
+typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
+typeof define === 'function' && define.amd ? define(['exports'], factory) :
+(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.d3 = global.d3 || {}));
+})(this, (function (exports) { 'use strict';
+
+function defaultSeparation$1(a, b) {
+  return a.parent === b.parent ? 1 : 2;
+}
+
+function meanX(children) {
+  return children.reduce(meanXReduce, 0) / children.length;
+}
+
+function meanXReduce(x, c) {
+  return x + c.x;
+}
+
+function maxY(children) {
+  return 1 + children.reduce(maxYReduce, 0);
+}
+
+function maxYReduce(y, c) {
+  return Math.max(y, c.y);
+}
+
+function leafLeft(node) {
+  var children;
+  while (children = node.children) node = children[0];
+  return node;
+}
+
+function leafRight(node) {
+  var children;
+  while (children = node.children) node = children[children.length - 1];
+  return node;
+}
+
+function cluster() {
+  var separation = defaultSeparation$1,
+      dx = 1,
+      dy = 1,
+      nodeSize = false;
+
+  function cluster(root) {
+    var previousNode,
+        x = 0;
+
+    // First walk, computing the initial x & y values.
+    root.eachAfter(function(node) {
+      var children = node.children;
+      if (children) {
+        node.x = meanX(children);
+        node.y = maxY(children);
+      } else {
+        node.x = previousNode ? x += separation(node, previousNode) : 0;
+        node.y = 0;
+        previousNode = node;
+      }
+    });
+
+    var left = leafLeft(root),
+        right = leafRight(root),
+        x0 = left.x - separation(left, right) / 2,
+        x1 = right.x + separation(right, left) / 2;
+
+    // Second walk, normalizing x & y to the desired size.
+    return root.eachAfter(nodeSize ? function(node) {
+      node.x = (node.x - root.x) * dx;
+      node.y = (root.y - node.y) * dy;
+    } : function(node) {
+      node.x = (node.x - x0) / (x1 - x0) * dx;
+      node.y = (1 - (root.y ? node.y / root.y : 1)) * dy;
+    });
+  }
+
+  cluster.separation = function(x) {
+    return arguments.length ? (separation = x, cluster) : separation;
+  };
+
+  cluster.size = function(x) {
+    return arguments.length ? (nodeSize = false, dx = +x[0], dy = +x[1], cluster) : (nodeSize ? null : [dx, dy]);
+  };
+
+  cluster.nodeSize = function(x) {
+    return arguments.length ? (nodeSize = true, dx = +x[0], dy = +x[1], cluster) : (nodeSize ? [dx, dy] : null);
+  };
+
+  return cluster;
+}
+
+function count(node) {
+  var sum = 0,
+      children = node.children,
+      i = children && children.length;
+  if (!i) sum = 1;
+  else while (--i >= 0) sum += children[i].value;
+  node.value = sum;
+}
+
+function node_count() {
+  return this.eachAfter(count);
+}
+
+function node_each(callback, that) {
+  let index = -1;
+  for (const node of this) {
+    callback.call(that, node, ++index, this);
+  }
+  return this;
+}
+
+function node_eachBefore(callback, that) {
+  var node = this, nodes = [node], children, i, index = -1;
+  while (node = nodes.pop()) {
+    callback.call(that, node, ++index, this);
+    if (children = node.children) {
+      for (i = children.length - 1; i >= 0; --i) {
+        nodes.push(children[i]);
+      }
+    }
+  }
+  return this;
+}
+
+function node_eachAfter(callback, that) {
+  var node = this, nodes = [node], next = [], children, i, n, index = -1;
+  while (node = nodes.pop()) {
+    next.push(node);
+    if (children = node.children) {
+      for (i = 0, n = children.length; i < n; ++i) {
+        nodes.push(children[i]);
+      }
+    }
+  }
+  while (node = next.pop()) {
+    callback.call(that, node, ++index, this);
+  }
+  return this;
+}
+
+function node_find(callback, that) {
+  let index = -1;
+  for (const node of this) {
+    if (callback.call(that, node, ++index, this)) {
+      return node;
+    }
+  }
+}
+
+function node_sum(value) {
+  return this.eachAfter(function(node) {
+    var sum = +value(node.data) || 0,
+        children = node.children,
+        i = children && children.length;
+    while (--i >= 0) sum += children[i].value;
+    node.value = sum;
+  });
+}
+
+function node_sort(compare) {
+  return this.eachBefore(function(node) {
+    if (node.children) {
+      node.children.sort(compare);
+    }
+  });
+}
+
+function node_path(end) {
+  var start = this,
+      ancestor = leastCommonAncestor(start, end),
+      nodes = [start];
+  while (start !== ancestor) {
+    start = start.parent;
+    nodes.push(start);
+  }
+  var k = nodes.length;
+  while (end !== ancestor) {
+    nodes.splice(k, 0, end);
+    end = end.parent;
+  }
+  return nodes;
+}
+
+function leastCommonAncestor(a, b) {
+  if (a === b) return a;
+  var aNodes = a.ancestors(),
+      bNodes = b.ancestors(),
+      c = null;
+  a = aNodes.pop();
+  b = bNodes.pop();
+  while (a === b) {
+    c = a;
+    a = aNodes.pop();
+    b = bNodes.pop();
+  }
+  return c;
+}
+
+function node_ancestors() {
+  var node = this, nodes = [node];
+  while (node = node.parent) {
+    nodes.push(node);
+  }
+  return nodes;
+}
+
+function node_descendants() {
+  return Array.from(this);
+}
+
+function node_leaves() {
+  var leaves = [];
+  this.eachBefore(function(node) {
+    if (!node.children) {
+      leaves.push(node);
+    }
+  });
+  return leaves;
+}
+
+function node_links() {
+  var root = this, links = [];
+  root.each(function(node) {
+    if (node !== root) { // Don’t include the root’s parent, if any.
+      links.push({source: node.parent, target: node});
+    }
+  });
+  return links;
+}
+
+function* node_iterator() {
+  var node = this, current, next = [node], children, i, n;
+  do {
+    current = next.reverse(), next = [];
+    while (node = current.pop()) {
+      yield node;
+      if (children = node.children) {
+        for (i = 0, n = children.length; i < n; ++i) {
+          next.push(children[i]);
+        }
+      }
+    }
+  } while (next.length);
+}
+
+function hierarchy(data, children) {
+  if (data instanceof Map) {
+    data = [undefined, data];
+    if (children === undefined) children = mapChildren;
+  } else if (children === undefined) {
+    children = objectChildren;
+  }
+
+  var root = new Node$1(data),
+      node,
+      nodes = [root],
+      child,
+      childs,
+      i,
+      n;
+
+  while (node = nodes.pop()) {
+    if ((childs = children(node.data)) && (n = (childs = Array.from(childs)).length)) {
+      node.children = childs;
+      for (i = n - 1; i >= 0; --i) {
+        nodes.push(child = childs[i] = new Node$1(childs[i]));
+        child.parent = node;
+        child.depth = node.depth + 1;
+      }
+    }
+  }
+
+  return root.eachBefore(computeHeight);
+}
+
+function node_copy() {
+  return hierarchy(this).eachBefore(copyData);
+}
+
+function objectChildren(d) {
+  return d.children;
+}
+
+function mapChildren(d) {
+  return Array.isArray(d) ? d[1] : null;
+}
+
+function copyData(node) {
+  if (node.data.value !== undefined) node.value = node.data.value;
+  node.data = node.data.data;
+}
+
+function computeHeight(node) {
+  var height = 0;
+  do node.height = height;
+  while ((node = node.parent) && (node.height < ++height));
+}
+
+function Node$1(data) {
+  this.data = data;
+  this.depth =
+  this.height = 0;
+  this.parent = null;
+}
+
+Node$1.prototype = hierarchy.prototype = {
+  constructor: Node$1,
+  count: node_count,
+  each: node_each,
+  eachAfter: node_eachAfter,
+  eachBefore: node_eachBefore,
+  find: node_find,
+  sum: node_sum,
+  sort: node_sort,
+  path: node_path,
+  ancestors: node_ancestors,
+  descendants: node_descendants,
+  leaves: node_leaves,
+  links: node_links,
+  copy: node_copy,
+  [Symbol.iterator]: node_iterator
+};
+
+function optional(f) {
+  return f == null ? null : required(f);
+}
+
+function required(f) {
+  if (typeof f !== "function") throw new Error;
+  return f;
+}
+
+function constantZero() {
+  return 0;
+}
+
+function constant(x) {
+  return function() {
+    return x;
+  };
+}
+
+// https://en.wikipedia.org/wiki/Linear_congruential_generator#Parameters_in_common_use
+const a = 1664525;
+const c = 1013904223;
+const m = 4294967296; // 2^32
+
+function lcg() {
+  let s = 1;
+  return () => (s = (a * s + c) % m) / m;
+}
+
+function array(x) {
+  return typeof x === "object" && "length" in x
+    ? x // Array, TypedArray, NodeList, array-like
+    : Array.from(x); // Map, Set, iterable, string, or anything else
+}
+
+function shuffle(array, random) {
+  let m = array.length,
+      t,
+      i;
+
+  while (m) {
+    i = random() * m-- | 0;
+    t = array[m];
+    array[m] = array[i];
+    array[i] = t;
+  }
+
+  return array;
+}
+
+function enclose(circles) {
+  return packEncloseRandom(circles, lcg());
+}
+
+function packEncloseRandom(circles, random) {
+  var i = 0, n = (circles = shuffle(Array.from(circles), random)).length, B = [], p, e;
+
+  while (i < n) {
+    p = circles[i];
+    if (e && enclosesWeak(e, p)) ++i;
+    else e = encloseBasis(B = extendBasis(B, p)), i = 0;
+  }
+
+  return e;
+}
+
+function extendBasis(B, p) {
+  var i, j;
+
+  if (enclosesWeakAll(p, B)) return [p];
+
+  // If we get here then B must have at least one element.
+  for (i = 0; i < B.length; ++i) {
+    if (enclosesNot(p, B[i])
+        && enclosesWeakAll(encloseBasis2(B[i], p), B)) {
+      return [B[i], p];
+    }
+  }
+
+  // If we get here then B must have at least two elements.
+  for (i = 0; i < B.length - 1; ++i) {
+    for (j = i + 1; j < B.length; ++j) {
+      if (enclosesNot(encloseBasis2(B[i], B[j]), p)
+          && enclosesNot(encloseBasis2(B[i], p), B[j])
+          && enclosesNot(encloseBasis2(B[j], p), B[i])
+          && enclosesWeakAll(encloseBasis3(B[i], B[j], p), B)) {
+        return [B[i], B[j], p];
+      }
+    }
+  }
+
+  // If we get here then something is very wrong.
+  throw new Error;
+}
+
+function enclosesNot(a, b) {
+  var dr = a.r - b.r, dx = b.x - a.x, dy = b.y - a.y;
+  return dr < 0 || dr * dr < dx * dx + dy * dy;
+}
+
+function enclosesWeak(a, b) {
+  var dr = a.r - b.r + Math.max(a.r, b.r, 1) * 1e-9, dx = b.x - a.x, dy = b.y - a.y;
+  return dr > 0 && dr * dr > dx * dx + dy * dy;
+}
+
+function enclosesWeakAll(a, B) {
+  for (var i = 0; i < B.length; ++i) {
+    if (!enclosesWeak(a, B[i])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+function encloseBasis(B) {
+  switch (B.length) {
+    case 1: return encloseBasis1(B[0]);
+    case 2: return encloseBasis2(B[0], B[1]);
+    case 3: return encloseBasis3(B[0], B[1], B[2]);
+  }
+}
+
+function encloseBasis1(a) {
+  return {
+    x: a.x,
+    y: a.y,
+    r: a.r
+  };
+}
+
+function encloseBasis2(a, b) {
+  var x1 = a.x, y1 = a.y, r1 = a.r,
+      x2 = b.x, y2 = b.y, r2 = b.r,
+      x21 = x2 - x1, y21 = y2 - y1, r21 = r2 - r1,
+      l = Math.sqrt(x21 * x21 + y21 * y21);
+  return {
+    x: (x1 + x2 + x21 / l * r21) / 2,
+    y: (y1 + y2 + y21 / l * r21) / 2,
+    r: (l + r1 + r2) / 2
+  };
+}
+
+function encloseBasis3(a, b, c) {
+  var x1 = a.x, y1 = a.y, r1 = a.r,
+      x2 = b.x, y2 = b.y, r2 = b.r,
+      x3 = c.x, y3 = c.y, r3 = c.r,
+      a2 = x1 - x2,
+      a3 = x1 - x3,
+      b2 = y1 - y2,
+      b3 = y1 - y3,
+      c2 = r2 - r1,
+      c3 = r3 - r1,
+      d1 = x1 * x1 + y1 * y1 - r1 * r1,
+      d2 = d1 - x2 * x2 - y2 * y2 + r2 * r2,
+      d3 = d1 - x3 * x3 - y3 * y3 + r3 * r3,
+      ab = a3 * b2 - a2 * b3,
+      xa = (b2 * d3 - b3 * d2) / (ab * 2) - x1,
+      xb = (b3 * c2 - b2 * c3) / ab,
+      ya = (a3 * d2 - a2 * d3) / (ab * 2) - y1,
+      yb = (a2 * c3 - a3 * c2) / ab,
+      A = xb * xb + yb * yb - 1,
+      B = 2 * (r1 + xa * xb + ya * yb),
+      C = xa * xa + ya * ya - r1 * r1,
+      r = -(Math.abs(A) > 1e-6 ? (B + Math.sqrt(B * B - 4 * A * C)) / (2 * A) : C / B);
+  return {
+    x: x1 + xa + xb * r,
+    y: y1 + ya + yb * r,
+    r: r
+  };
+}
+
+function place(b, a, c) {
+  var dx = b.x - a.x, x, a2,
+      dy = b.y - a.y, y, b2,
+      d2 = dx * dx + dy * dy;
+  if (d2) {
+    a2 = a.r + c.r, a2 *= a2;
+    b2 = b.r + c.r, b2 *= b2;
+    if (a2 > b2) {
+      x = (d2 + b2 - a2) / (2 * d2);
+      y = Math.sqrt(Math.max(0, b2 / d2 - x * x));
+      c.x = b.x - x * dx - y * dy;
+      c.y = b.y - x * dy + y * dx;
+    } else {
+      x = (d2 + a2 - b2) / (2 * d2);
+      y = Math.sqrt(Math.max(0, a2 / d2 - x * x));
+      c.x = a.x + x * dx - y * dy;
+      c.y = a.y + x * dy + y * dx;
+    }
+  } else {
+    c.x = a.x + c.r;
+    c.y = a.y;
+  }
+}
+
+function intersects(a, b) {
+  var dr = a.r + b.r - 1e-6, dx = b.x - a.x, dy = b.y - a.y;
+  return dr > 0 && dr * dr > dx * dx + dy * dy;
+}
+
+function score(node) {
+  var a = node._,
+      b = node.next._,
+      ab = a.r + b.r,
+      dx = (a.x * b.r + b.x * a.r) / ab,
+      dy = (a.y * b.r + b.y * a.r) / ab;
+  return dx * dx + dy * dy;
+}
+
+function Node(circle) {
+  this._ = circle;
+  this.next = null;
+  this.previous = null;
+}
+
+function packSiblingsRandom(circles, random) {
+  if (!(n = (circles = array(circles)).length)) return 0;
+
+  var a, b, c, n, aa, ca, i, j, k, sj, sk;
+
+  // Place the first circle.
+  a = circles[0], a.x = 0, a.y = 0;
+  if (!(n > 1)) return a.r;
+
+  // Place the second circle.
+  b = circles[1], a.x = -b.r, b.x = a.r, b.y = 0;
+  if (!(n > 2)) return a.r + b.r;
+
+  // Place the third circle.
+  place(b, a, c = circles[2]);
+
+  // Initialize the front-chain using the first three circles a, b and c.
+  a = new Node(a), b = new Node(b), c = new Node(c);
+  a.next = c.previous = b;
+  b.next = a.previous = c;
+  c.next = b.previous = a;
+
+  // Attempt to place each remaining circle…
+  pack: for (i = 3; i < n; ++i) {
+    place(a._, b._, c = circles[i]), c = new Node(c);
+
+    // Find the closest intersecting circle on the front-chain, if any.
+    // “Closeness” is determined by linear distance along the front-chain.
+    // “Ahead” or “behind” is likewise determined by linear distance.
+    j = b.next, k = a.previous, sj = b._.r, sk = a._.r;
+    do {
+      if (sj <= sk) {
+        if (intersects(j._, c._)) {
+          b = j, a.next = b, b.previous = a, --i;
+          continue pack;
+        }
+        sj += j._.r, j = j.next;
+      } else {
+        if (intersects(k._, c._)) {
+          a = k, a.next = b, b.previous = a, --i;
+          continue pack;
+        }
+        sk += k._.r, k = k.previous;
+      }
+    } while (j !== k.next);
+
+    // Success! Insert the new circle c between a and b.
+    c.previous = a, c.next = b, a.next = b.previous = b = c;
+
+    // Compute the new closest circle pair to the centroid.
+    aa = score(a);
+    while ((c = c.next) !== b) {
+      if ((ca = score(c)) < aa) {
+        a = c, aa = ca;
+      }
+    }
+    b = a.next;
+  }
+
+  // Compute the enclosing circle of the front chain.
+  a = [b._], c = b; while ((c = c.next) !== b) a.push(c._); c = packEncloseRandom(a, random);
+
+  // Translate the circles to put the enclosing circle around the origin.
+  for (i = 0; i < n; ++i) a = circles[i], a.x -= c.x, a.y -= c.y;
+
+  return c.r;
+}
+
+function siblings(circles) {
+  packSiblingsRandom(circles, lcg());
+  return circles;
+}
+
+function defaultRadius(d) {
+  return Math.sqrt(d.value);
+}
+
+function index$1() {
+  var radius = null,
+      dx = 1,
+      dy = 1,
+      padding = constantZero;
+
+  function pack(root) {
+    const random = lcg();
+    root.x = dx / 2, root.y = dy / 2;
+    if (radius) {
+      root.eachBefore(radiusLeaf(radius))
+          .eachAfter(packChildrenRandom(padding, 0.5, random))
+          .eachBefore(translateChild(1));
+    } else {
+      root.eachBefore(radiusLeaf(defaultRadius))
+          .eachAfter(packChildrenRandom(constantZero, 1, random))
+          .eachAfter(packChildrenRandom(padding, root.r / Math.min(dx, dy), random))
+          .eachBefore(translateChild(Math.min(dx, dy) / (2 * root.r)));
+    }
+    return root;
+  }
+
+  pack.radius = function(x) {
+    return arguments.length ? (radius = optional(x), pack) : radius;
+  };
+
+  pack.size = function(x) {
+    return arguments.length ? (dx = +x[0], dy = +x[1], pack) : [dx, dy];
+  };
+
+  pack.padding = function(x) {
+    return arguments.length ? (padding = typeof x === "function" ? x : constant(+x), pack) : padding;
+  };
+
+  return pack;
+}
+
+function radiusLeaf(radius) {
+  return function(node) {
+    if (!node.children) {
+      node.r = Math.max(0, +radius(node) || 0);
+    }
+  };
+}
+
+function packChildrenRandom(padding, k, random) {
+  return function(node) {
+    if (children = node.children) {
+      var children,
+          i,
+          n = children.length,
+          r = padding(node) * k || 0,
+          e;
+
+      if (r) for (i = 0; i < n; ++i) children[i].r += r;
+      e = packSiblingsRandom(children, random);
+      if (r) for (i = 0; i < n; ++i) children[i].r -= r;
+      node.r = e + r;
+    }
+  };
+}
+
+function translateChild(k) {
+  return function(node) {
+    var parent = node.parent;
+    node.r *= k;
+    if (parent) {
+      node.x = parent.x + k * node.x;
+      node.y = parent.y + k * node.y;
+    }
+  };
+}
+
+function roundNode(node) {
+  node.x0 = Math.round(node.x0);
+  node.y0 = Math.round(node.y0);
+  node.x1 = Math.round(node.x1);
+  node.y1 = Math.round(node.y1);
+}
+
+function treemapDice(parent, x0, y0, x1, y1) {
+  var nodes = parent.children,
+      node,
+      i = -1,
+      n = nodes.length,
+      k = parent.value && (x1 - x0) / parent.value;
+
+  while (++i < n) {
+    node = nodes[i], node.y0 = y0, node.y1 = y1;
+    node.x0 = x0, node.x1 = x0 += node.value * k;
+  }
+}
+
+function partition() {
+  var dx = 1,
+      dy = 1,
+      padding = 0,
+      round = false;
+
+  function partition(root) {
+    var n = root.height + 1;
+    root.x0 =
+    root.y0 = padding;
+    root.x1 = dx;
+    root.y1 = dy / n;
+    root.eachBefore(positionNode(dy, n));
+    if (round) root.eachBefore(roundNode);
+    return root;
+  }
+
+  function positionNode(dy, n) {
+    return function(node) {
+      if (node.children) {
+        treemapDice(node, node.x0, dy * (node.depth + 1) / n, node.x1, dy * (node.depth + 2) / n);
+      }
+      var x0 = node.x0,
+          y0 = node.y0,
+          x1 = node.x1 - padding,
+          y1 = node.y1 - padding;
+      if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
+      if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
+      node.x0 = x0;
+      node.y0 = y0;
+      node.x1 = x1;
+      node.y1 = y1;
+    };
+  }
+
+  partition.round = function(x) {
+    return arguments.length ? (round = !!x, partition) : round;
+  };
+
+  partition.size = function(x) {
+    return arguments.length ? (dx = +x[0], dy = +x[1], partition) : [dx, dy];
+  };
+
+  partition.padding = function(x) {
+    return arguments.length ? (padding = +x, partition) : padding;
+  };
+
+  return partition;
+}
+
+var preroot = {depth: -1},
+    ambiguous = {},
+    imputed = {};
+
+function defaultId(d) {
+  return d.id;
+}
+
+function defaultParentId(d) {
+  return d.parentId;
+}
+
+function stratify() {
+  var id = defaultId,
+      parentId = defaultParentId,
+      path;
+
+  function stratify(data) {
+    var nodes = Array.from(data),
+        currentId = id,
+        currentParentId = parentId,
+        n,
+        d,
+        i,
+        root,
+        parent,
+        node,
+        nodeId,
+        nodeKey,
+        nodeByKey = new Map;
+
+    if (path != null) {
+      const I = nodes.map((d, i) => normalize(path(d, i, data)));
+      const P = I.map(parentof);
+      const S = new Set(I).add("");
+      for (const i of P) {
+        if (!S.has(i)) {
+          S.add(i);
+          I.push(i);
+          P.push(parentof(i));
+          nodes.push(imputed);
+        }
+      }
+      currentId = (_, i) => I[i];
+      currentParentId = (_, i) => P[i];
+    }
+
+    for (i = 0, n = nodes.length; i < n; ++i) {
+      d = nodes[i], node = nodes[i] = new Node$1(d);
+      if ((nodeId = currentId(d, i, data)) != null && (nodeId += "")) {
+        nodeKey = node.id = nodeId;
+        nodeByKey.set(nodeKey, nodeByKey.has(nodeKey) ? ambiguous : node);
+      }
+      if ((nodeId = currentParentId(d, i, data)) != null && (nodeId += "")) {
+        node.parent = nodeId;
+      }
+    }
+
+    for (i = 0; i < n; ++i) {
+      node = nodes[i];
+      if (nodeId = node.parent) {
+        parent = nodeByKey.get(nodeId);
+        if (!parent) throw new Error("missing: " + nodeId);
+        if (parent === ambiguous) throw new Error("ambiguous: " + nodeId);
+        if (parent.children) parent.children.push(node);
+        else parent.children = [node];
+        node.parent = parent;
+      } else {
+        if (root) throw new Error("multiple roots");
+        root = node;
+      }
+    }
+
+    if (!root) throw new Error("no root");
+
+    // When imputing internal nodes, only introduce roots if needed.
+    // Then replace the imputed marker data with null.
+    if (path != null) {
+      while (root.data === imputed && root.children.length === 1) {
+        root = root.children[0], --n;
+      }
+      for (let i = nodes.length - 1; i >= 0; --i) {
+        node = nodes[i];
+        if (node.data !== imputed) break;
+        node.data = null;
+      }
+    }
+
+    root.parent = preroot;
+    root.eachBefore(function(node) { node.depth = node.parent.depth + 1; --n; }).eachBefore(computeHeight);
+    root.parent = null;
+    if (n > 0) throw new Error("cycle");
+
+    return root;
+  }
+
+  stratify.id = function(x) {
+    return arguments.length ? (id = optional(x), stratify) : id;
+  };
+
+  stratify.parentId = function(x) {
+    return arguments.length ? (parentId = optional(x), stratify) : parentId;
+  };
+
+  stratify.path = function(x) {
+    return arguments.length ? (path = optional(x), stratify) : path;
+  };
+
+  return stratify;
+}
+
+// To normalize a path, we coerce to a string, strip the trailing slash if any
+// (as long as the trailing slash is not immediately preceded by another slash),
+// and add leading slash if missing.
+function normalize(path) {
+  path = `${path}`;
+  let i = path.length;
+  if (slash(path, i - 1) && !slash(path, i - 2)) path = path.slice(0, -1);
+  return path[0] === "/" ? path : `/${path}`;
+}
+
+// Walk backwards to find the first slash that is not the leading slash, e.g.:
+// "/foo/bar" ⇥ "/foo", "/foo" ⇥ "/", "/" ↦ "". (The root is special-cased
+// because the id of the root must be a truthy value.)
+function parentof(path) {
+  let i = path.length;
+  if (i < 2) return "";
+  while (--i > 1) if (slash(path, i)) break;
+  return path.slice(0, i);
+}
+
+// Slashes can be escaped; to determine whether a slash is a path delimiter, we
+// count the number of preceding backslashes escaping the forward slash: an odd
+// number indicates an escaped forward slash.
+function slash(path, i) {
+  if (path[i] === "/") {
+    let k = 0;
+    while (i > 0 && path[--i] === "\\") ++k;
+    if ((k & 1) === 0) return true;
+  }
+  return false;
+}
+
+function defaultSeparation(a, b) {
+  return a.parent === b.parent ? 1 : 2;
+}
+
+// function radialSeparation(a, b) {
+//   return (a.parent === b.parent ? 1 : 2) / a.depth;
+// }
+
+// This function is used to traverse the left contour of a subtree (or
+// subforest). It returns the successor of v on this contour. This successor is
+// either given by the leftmost child of v or by the thread of v. The function
+// returns null if and only if v is on the highest level of its subtree.
+function nextLeft(v) {
+  var children = v.children;
+  return children ? children[0] : v.t;
+}
+
+// This function works analogously to nextLeft.
+function nextRight(v) {
+  var children = v.children;
+  return children ? children[children.length - 1] : v.t;
+}
+
+// Shifts the current subtree rooted at w+. This is done by increasing
+// prelim(w+) and mod(w+) by shift.
+function moveSubtree(wm, wp, shift) {
+  var change = shift / (wp.i - wm.i);
+  wp.c -= change;
+  wp.s += shift;
+  wm.c += change;
+  wp.z += shift;
+  wp.m += shift;
+}
+
+// All other shifts, applied to the smaller subtrees between w- and w+, are
+// performed by this function. To prepare the shifts, we have to adjust
+// change(w+), shift(w+), and change(w-).
+function executeShifts(v) {
+  var shift = 0,
+      change = 0,
+      children = v.children,
+      i = children.length,
+      w;
+  while (--i >= 0) {
+    w = children[i];
+    w.z += shift;
+    w.m += shift;
+    shift += w.s + (change += w.c);
+  }
+}
+
+// If vi-’s ancestor is a sibling of v, returns vi-’s ancestor. Otherwise,
+// returns the specified (default) ancestor.
+function nextAncestor(vim, v, ancestor) {
+  return vim.a.parent === v.parent ? vim.a : ancestor;
+}
+
+function TreeNode(node, i) {
+  this._ = node;
+  this.parent = null;
+  this.children = null;
+  this.A = null; // default ancestor
+  this.a = this; // ancestor
+  this.z = 0; // prelim
+  this.m = 0; // mod
+  this.c = 0; // change
+  this.s = 0; // shift
+  this.t = null; // thread
+  this.i = i; // number
+}
+
+TreeNode.prototype = Object.create(Node$1.prototype);
+
+function treeRoot(root) {
+  var tree = new TreeNode(root, 0),
+      node,
+      nodes = [tree],
+      child,
+      children,
+      i,
+      n;
+
+  while (node = nodes.pop()) {
+    if (children = node._.children) {
+      node.children = new Array(n = children.length);
+      for (i = n - 1; i >= 0; --i) {
+        nodes.push(child = node.children[i] = new TreeNode(children[i], i));
+        child.parent = node;
+      }
+    }
+  }
+
+  (tree.parent = new TreeNode(null, 0)).children = [tree];
+  return tree;
+}
+
+// Node-link tree diagram using the Reingold-Tilford "tidy" algorithm
+function tree() {
+  var separation = defaultSeparation,
+      dx = 1,
+      dy = 1,
+      nodeSize = null;
+
+  function tree(root) {
+    var t = treeRoot(root);
+
+    // Compute the layout using Buchheim et al.’s algorithm.
+    t.eachAfter(firstWalk), t.parent.m = -t.z;
+    t.eachBefore(secondWalk);
+
+    // If a fixed node size is specified, scale x and y.
+    if (nodeSize) root.eachBefore(sizeNode);
+
+    // If a fixed tree size is specified, scale x and y based on the extent.
+    // Compute the left-most, right-most, and depth-most nodes for extents.
+    else {
+      var left = root,
+          right = root,
+          bottom = root;
+      root.eachBefore(function(node) {
+        if (node.x < left.x) left = node;
+        if (node.x > right.x) right = node;
+        if (node.depth > bottom.depth) bottom = node;
+      });
+      var s = left === right ? 1 : separation(left, right) / 2,
+          tx = s - left.x,
+          kx = dx / (right.x + s + tx),
+          ky = dy / (bottom.depth || 1);
+      root.eachBefore(function(node) {
+        node.x = (node.x + tx) * kx;
+        node.y = node.depth * ky;
+      });
+    }
+
+    return root;
+  }
+
+  // Computes a preliminary x-coordinate for v. Before that, FIRST WALK is
+  // applied recursively to the children of v, as well as the function
+  // APPORTION. After spacing out the children by calling EXECUTE SHIFTS, the
+  // node v is placed to the midpoint of its outermost children.
+  function firstWalk(v) {
+    var children = v.children,
+        siblings = v.parent.children,
+        w = v.i ? siblings[v.i - 1] : null;
+    if (children) {
+      executeShifts(v);
+      var midpoint = (children[0].z + children[children.length - 1].z) / 2;
+      if (w) {
+        v.z = w.z + separation(v._, w._);
+        v.m = v.z - midpoint;
+      } else {
+        v.z = midpoint;
+      }
+    } else if (w) {
+      v.z = w.z + separation(v._, w._);
+    }
+    v.parent.A = apportion(v, w, v.parent.A || siblings[0]);
+  }
+
+  // Computes all real x-coordinates by summing up the modifiers recursively.
+  function secondWalk(v) {
+    v._.x = v.z + v.parent.m;
+    v.m += v.parent.m;
+  }
+
+  // The core of the algorithm. Here, a new subtree is combined with the
+  // previous subtrees. Threads are used to traverse the inside and outside
+  // contours of the left and right subtree up to the highest common level. The
+  // vertices used for the traversals are vi+, vi-, vo-, and vo+, where the
+  // superscript o means outside and i means inside, the subscript - means left
+  // subtree and + means right subtree. For summing up the modifiers along the
+  // contour, we use respective variables si+, si-, so-, and so+. Whenever two
+  // nodes of the inside contours conflict, we compute the left one of the
+  // greatest uncommon ancestors using the function ANCESTOR and call MOVE
+  // SUBTREE to shift the subtree and prepare the shifts of smaller subtrees.
+  // Finally, we add a new thread (if necessary).
+  function apportion(v, w, ancestor) {
+    if (w) {
+      var vip = v,
+          vop = v,
+          vim = w,
+          vom = vip.parent.children[0],
+          sip = vip.m,
+          sop = vop.m,
+          sim = vim.m,
+          som = vom.m,
+          shift;
+      while (vim = nextRight(vim), vip = nextLeft(vip), vim && vip) {
+        vom = nextLeft(vom);
+        vop = nextRight(vop);
+        vop.a = v;
+        shift = vim.z + sim - vip.z - sip + separation(vim._, vip._);
+        if (shift > 0) {
+          moveSubtree(nextAncestor(vim, v, ancestor), v, shift);
+          sip += shift;
+          sop += shift;
+        }
+        sim += vim.m;
+        sip += vip.m;
+        som += vom.m;
+        sop += vop.m;
+      }
+      if (vim && !nextRight(vop)) {
+        vop.t = vim;
+        vop.m += sim - sop;
+      }
+      if (vip && !nextLeft(vom)) {
+        vom.t = vip;
+        vom.m += sip - som;
+        ancestor = v;
+      }
+    }
+    return ancestor;
+  }
+
+  function sizeNode(node) {
+    node.x *= dx;
+    node.y = node.depth * dy;
+  }
+
+  tree.separation = function(x) {
+    return arguments.length ? (separation = x, tree) : separation;
+  };
+
+  tree.size = function(x) {
+    return arguments.length ? (nodeSize = false, dx = +x[0], dy = +x[1], tree) : (nodeSize ? null : [dx, dy]);
+  };
+
+  tree.nodeSize = function(x) {
+    return arguments.length ? (nodeSize = true, dx = +x[0], dy = +x[1], tree) : (nodeSize ? [dx, dy] : null);
+  };
+
+  return tree;
+}
+
+function treemapSlice(parent, x0, y0, x1, y1) {
+  var nodes = parent.children,
+      node,
+      i = -1,
+      n = nodes.length,
+      k = parent.value && (y1 - y0) / parent.value;
+
+  while (++i < n) {
+    node = nodes[i], node.x0 = x0, node.x1 = x1;
+    node.y0 = y0, node.y1 = y0 += node.value * k;
+  }
+}
+
+var phi = (1 + Math.sqrt(5)) / 2;
+
+function squarifyRatio(ratio, parent, x0, y0, x1, y1) {
+  var rows = [],
+      nodes = parent.children,
+      row,
+      nodeValue,
+      i0 = 0,
+      i1 = 0,
+      n = nodes.length,
+      dx, dy,
+      value = parent.value,
+      sumValue,
+      minValue,
+      maxValue,
+      newRatio,
+      minRatio,
+      alpha,
+      beta;
+
+  while (i0 < n) {
+    dx = x1 - x0, dy = y1 - y0;
+
+    // Find the next non-empty node.
+    do sumValue = nodes[i1++].value; while (!sumValue && i1 < n);
+    minValue = maxValue = sumValue;
+    alpha = Math.max(dy / dx, dx / dy) / (value * ratio);
+    beta = sumValue * sumValue * alpha;
+    minRatio = Math.max(maxValue / beta, beta / minValue);
+
+    // Keep adding nodes while the aspect ratio maintains or improves.
+    for (; i1 < n; ++i1) {
+      sumValue += nodeValue = nodes[i1].value;
+      if (nodeValue < minValue) minValue = nodeValue;
+      if (nodeValue > maxValue) maxValue = nodeValue;
+      beta = sumValue * sumValue * alpha;
+      newRatio = Math.max(maxValue / beta, beta / minValue);
+      if (newRatio > minRatio) { sumValue -= nodeValue; break; }
+      minRatio = newRatio;
+    }
+
+    // Position and record the row orientation.
+    rows.push(row = {value: sumValue, dice: dx < dy, children: nodes.slice(i0, i1)});
+    if (row.dice) treemapDice(row, x0, y0, x1, value ? y0 += dy * sumValue / value : y1);
+    else treemapSlice(row, x0, y0, value ? x0 += dx * sumValue / value : x1, y1);
+    value -= sumValue, i0 = i1;
+  }
+
+  return rows;
+}
+
+var squarify = (function custom(ratio) {
+
+  function squarify(parent, x0, y0, x1, y1) {
+    squarifyRatio(ratio, parent, x0, y0, x1, y1);
+  }
+
+  squarify.ratio = function(x) {
+    return custom((x = +x) > 1 ? x : 1);
+  };
+
+  return squarify;
+})(phi);
+
+function index() {
+  var tile = squarify,
+      round = false,
+      dx = 1,
+      dy = 1,
+      paddingStack = [0],
+      paddingInner = constantZero,
+      paddingTop = constantZero,
+      paddingRight = constantZero,
+      paddingBottom = constantZero,
+      paddingLeft = constantZero;
+
+  function treemap(root) {
+    root.x0 =
+    root.y0 = 0;
+    root.x1 = dx;
+    root.y1 = dy;
+    root.eachBefore(positionNode);
+    paddingStack = [0];
+    if (round) root.eachBefore(roundNode);
+    return root;
+  }
+
+  function positionNode(node) {
+    var p = paddingStack[node.depth],
+        x0 = node.x0 + p,
+        y0 = node.y0 + p,
+        x1 = node.x1 - p,
+        y1 = node.y1 - p;
+    if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
+    if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
+    node.x0 = x0;
+    node.y0 = y0;
+    node.x1 = x1;
+    node.y1 = y1;
+    if (node.children) {
+      p = paddingStack[node.depth + 1] = paddingInner(node) / 2;
+      x0 += paddingLeft(node) - p;
+      y0 += paddingTop(node) - p;
+      x1 -= paddingRight(node) - p;
+      y1 -= paddingBottom(node) - p;
+      if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
+      if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
+      tile(node, x0, y0, x1, y1);
+    }
+  }
+
+  treemap.round = function(x) {
+    return arguments.length ? (round = !!x, treemap) : round;
+  };
+
+  treemap.size = function(x) {
+    return arguments.length ? (dx = +x[0], dy = +x[1], treemap) : [dx, dy];
+  };
+
+  treemap.tile = function(x) {
+    return arguments.length ? (tile = required(x), treemap) : tile;
+  };
+
+  treemap.padding = function(x) {
+    return arguments.length ? treemap.paddingInner(x).paddingOuter(x) : treemap.paddingInner();
+  };
+
+  treemap.paddingInner = function(x) {
+    return arguments.length ? (paddingInner = typeof x === "function" ? x : constant(+x), treemap) : paddingInner;
+  };
+
+  treemap.paddingOuter = function(x) {
+    return arguments.length ? treemap.paddingTop(x).paddingRight(x).paddingBottom(x).paddingLeft(x) : treemap.paddingTop();
+  };
+
+  treemap.paddingTop = function(x) {
+    return arguments.length ? (paddingTop = typeof x === "function" ? x : constant(+x), treemap) : paddingTop;
+  };
+
+  treemap.paddingRight = function(x) {
+    return arguments.length ? (paddingRight = typeof x === "function" ? x : constant(+x), treemap) : paddingRight;
+  };
+
+  treemap.paddingBottom = function(x) {
+    return arguments.length ? (paddingBottom = typeof x === "function" ? x : constant(+x), treemap) : paddingBottom;
+  };
+
+  treemap.paddingLeft = function(x) {
+    return arguments.length ? (paddingLeft = typeof x === "function" ? x : constant(+x), treemap) : paddingLeft;
+  };
+
+  return treemap;
+}
+
+function binary(parent, x0, y0, x1, y1) {
+  var nodes = parent.children,
+      i, n = nodes.length,
+      sum, sums = new Array(n + 1);
+
+  for (sums[0] = sum = i = 0; i < n; ++i) {
+    sums[i + 1] = sum += nodes[i].value;
+  }
+
+  partition(0, n, parent.value, x0, y0, x1, y1);
+
+  function partition(i, j, value, x0, y0, x1, y1) {
+    if (i >= j - 1) {
+      var node = nodes[i];
+      node.x0 = x0, node.y0 = y0;
+      node.x1 = x1, node.y1 = y1;
+      return;
+    }
+
+    var valueOffset = sums[i],
+        valueTarget = (value / 2) + valueOffset,
+        k = i + 1,
+        hi = j - 1;
+
+    while (k < hi) {
+      var mid = k + hi >>> 1;
+      if (sums[mid] < valueTarget) k = mid + 1;
+      else hi = mid;
+    }
+
+    if ((valueTarget - sums[k - 1]) < (sums[k] - valueTarget) && i + 1 < k) --k;
+
+    var valueLeft = sums[k] - valueOffset,
+        valueRight = value - valueLeft;
+
+    if ((x1 - x0) > (y1 - y0)) {
+      var xk = value ? (x0 * valueRight + x1 * valueLeft) / value : x1;
+      partition(i, k, valueLeft, x0, y0, xk, y1);
+      partition(k, j, valueRight, xk, y0, x1, y1);
+    } else {
+      var yk = value ? (y0 * valueRight + y1 * valueLeft) / value : y1;
+      partition(i, k, valueLeft, x0, y0, x1, yk);
+      partition(k, j, valueRight, x0, yk, x1, y1);
+    }
+  }
+}
+
+function sliceDice(parent, x0, y0, x1, y1) {
+  (parent.depth & 1 ? treemapSlice : treemapDice)(parent, x0, y0, x1, y1);
+}
+
+var resquarify = (function custom(ratio) {
+
+  function resquarify(parent, x0, y0, x1, y1) {
+    if ((rows = parent._squarify) && (rows.ratio === ratio)) {
+      var rows,
+          row,
+          nodes,
+          i,
+          j = -1,
+          n,
+          m = rows.length,
+          value = parent.value;
+
+      while (++j < m) {
+        row = rows[j], nodes = row.children;
+        for (i = row.value = 0, n = nodes.length; i < n; ++i) row.value += nodes[i].value;
+        if (row.dice) treemapDice(row, x0, y0, x1, value ? y0 += (y1 - y0) * row.value / value : y1);
+        else treemapSlice(row, x0, y0, value ? x0 += (x1 - x0) * row.value / value : x1, y1);
+        value -= row.value;
+      }
+    } else {
+      parent._squarify = rows = squarifyRatio(ratio, parent, x0, y0, x1, y1);
+      rows.ratio = ratio;
+    }
+  }
+
+  resquarify.ratio = function(x) {
+    return custom((x = +x) > 1 ? x : 1);
+  };
+
+  return resquarify;
+})(phi);
+
+exports.Node = Node$1;
+exports.cluster = cluster;
+exports.hierarchy = hierarchy;
+exports.pack = index$1;
+exports.packEnclose = enclose;
+exports.packSiblings = siblings;
+exports.partition = partition;
+exports.stratify = stratify;
+exports.tree = tree;
+exports.treemap = index;
+exports.treemapBinary = binary;
+exports.treemapDice = treemapDice;
+exports.treemapResquarify = resquarify;
+exports.treemapSlice = treemapSlice;
+exports.treemapSliceDice = sliceDice;
+exports.treemapSquarify = squarify;
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+}));