Index: node_modules/d3-quadtree/src/visit.js
===================================================================
--- node_modules/d3-quadtree/src/visit.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-quadtree/src/visit.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,16 @@
+import Quad from "./quad.js";
+
+export default function(callback) {
+  var quads = [], q, node = this._root, child, x0, y0, x1, y1;
+  if (node) quads.push(new Quad(node, this._x0, this._y0, this._x1, this._y1));
+  while (q = quads.pop()) {
+    if (!callback(node = q.node, x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1) && node.length) {
+      var xm = (x0 + x1) / 2, ym = (y0 + y1) / 2;
+      if (child = node[3]) quads.push(new Quad(child, xm, ym, x1, y1));
+      if (child = node[2]) quads.push(new Quad(child, x0, ym, xm, y1));
+      if (child = node[1]) quads.push(new Quad(child, xm, y0, x1, ym));
+      if (child = node[0]) quads.push(new Quad(child, x0, y0, xm, ym));
+    }
+  }
+  return this;
+}