Index: node_modules/d3-quadtree/src/remove.js
===================================================================
--- node_modules/d3-quadtree/src/remove.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-quadtree/src/remove.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,62 @@
+export default function(d) {
+  if (isNaN(x = +this._x.call(null, d)) || isNaN(y = +this._y.call(null, d))) return this; // ignore invalid points
+
+  var parent,
+      node = this._root,
+      retainer,
+      previous,
+      next,
+      x0 = this._x0,
+      y0 = this._y0,
+      x1 = this._x1,
+      y1 = this._y1,
+      x,
+      y,
+      xm,
+      ym,
+      right,
+      bottom,
+      i,
+      j;
+
+  // If the tree is empty, initialize the root as a leaf.
+  if (!node) return this;
+
+  // Find the leaf node for the point.
+  // While descending, also retain the deepest parent with a non-removed sibling.
+  if (node.length) while (true) {
+    if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
+    if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
+    if (!(parent = node, node = node[i = bottom << 1 | right])) return this;
+    if (!node.length) break;
+    if (parent[(i + 1) & 3] || parent[(i + 2) & 3] || parent[(i + 3) & 3]) retainer = parent, j = i;
+  }
+
+  // Find the point to remove.
+  while (node.data !== d) if (!(previous = node, node = node.next)) return this;
+  if (next = node.next) delete node.next;
+
+  // If there are multiple coincident points, remove just the point.
+  if (previous) return (next ? previous.next = next : delete previous.next), this;
+
+  // If this is the root point, remove it.
+  if (!parent) return this._root = next, this;
+
+  // Remove this leaf.
+  next ? parent[i] = next : delete parent[i];
+
+  // If the parent now contains exactly one leaf, collapse superfluous parents.
+  if ((node = parent[0] || parent[1] || parent[2] || parent[3])
+      && node === (parent[3] || parent[2] || parent[1] || parent[0])
+      && !node.length) {
+    if (retainer) retainer[j] = node;
+    else this._root = node;
+  }
+
+  return this;
+}
+
+export function removeAll(data) {
+  for (var i = 0, n = data.length; i < n; ++i) this.remove(data[i]);
+  return this;
+}