Index: node_modules/d3-hierarchy/src/pack/siblings.js
===================================================================
--- node_modules/d3-hierarchy/src/pack/siblings.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-hierarchy/src/pack/siblings.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,120 @@
+import array from "../array.js";
+import lcg from "../lcg.js";
+import {packEncloseRandom} from "./enclose.js";
+
+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;
+}
+
+export 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;
+}
+
+export default function(circles) {
+  packSiblingsRandom(circles, lcg());
+  return circles;
+}