Index: node_modules/d3-force/src/collide.js
===================================================================
--- node_modules/d3-force/src/collide.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-force/src/collide.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,100 @@
+import {quadtree} from "d3-quadtree";
+import constant from "./constant.js";
+import jiggle from "./jiggle.js";
+
+function x(d) {
+  return d.x + d.vx;
+}
+
+function y(d) {
+  return d.y + d.vy;
+}
+
+export default function(radius) {
+  var nodes,
+      radii,
+      random,
+      strength = 1,
+      iterations = 1;
+
+  if (typeof radius !== "function") radius = constant(radius == null ? 1 : +radius);
+
+  function force() {
+    var i, n = nodes.length,
+        tree,
+        node,
+        xi,
+        yi,
+        ri,
+        ri2;
+
+    for (var k = 0; k < iterations; ++k) {
+      tree = quadtree(nodes, x, y).visitAfter(prepare);
+      for (i = 0; i < n; ++i) {
+        node = nodes[i];
+        ri = radii[node.index], ri2 = ri * ri;
+        xi = node.x + node.vx;
+        yi = node.y + node.vy;
+        tree.visit(apply);
+      }
+    }
+
+    function apply(quad, x0, y0, x1, y1) {
+      var data = quad.data, rj = quad.r, r = ri + rj;
+      if (data) {
+        if (data.index > node.index) {
+          var x = xi - data.x - data.vx,
+              y = yi - data.y - data.vy,
+              l = x * x + y * y;
+          if (l < r * r) {
+            if (x === 0) x = jiggle(random), l += x * x;
+            if (y === 0) y = jiggle(random), l += y * y;
+            l = (r - (l = Math.sqrt(l))) / l * strength;
+            node.vx += (x *= l) * (r = (rj *= rj) / (ri2 + rj));
+            node.vy += (y *= l) * r;
+            data.vx -= x * (r = 1 - r);
+            data.vy -= y * r;
+          }
+        }
+        return;
+      }
+      return x0 > xi + r || x1 < xi - r || y0 > yi + r || y1 < yi - r;
+    }
+  }
+
+  function prepare(quad) {
+    if (quad.data) return quad.r = radii[quad.data.index];
+    for (var i = quad.r = 0; i < 4; ++i) {
+      if (quad[i] && quad[i].r > quad.r) {
+        quad.r = quad[i].r;
+      }
+    }
+  }
+
+  function initialize() {
+    if (!nodes) return;
+    var i, n = nodes.length, node;
+    radii = new Array(n);
+    for (i = 0; i < n; ++i) node = nodes[i], radii[node.index] = +radius(node, i, nodes);
+  }
+
+  force.initialize = function(_nodes, _random) {
+    nodes = _nodes;
+    random = _random;
+    initialize();
+  };
+
+  force.iterations = function(_) {
+    return arguments.length ? (iterations = +_, force) : iterations;
+  };
+
+  force.strength = function(_) {
+    return arguments.length ? (strength = +_, force) : strength;
+  };
+
+  force.radius = function(_) {
+    return arguments.length ? (radius = typeof _ === "function" ? _ : constant(+_), initialize(), force) : radius;
+  };
+
+  return force;
+}