Index: node_modules/d3-timer/src/timer.js
===================================================================
--- node_modules/d3-timer/src/timer.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-timer/src/timer.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,110 @@
+var frame = 0, // is an animation frame pending?
+    timeout = 0, // is a timeout pending?
+    interval = 0, // are any timers active?
+    pokeDelay = 1000, // how frequently we check for clock skew
+    taskHead,
+    taskTail,
+    clockLast = 0,
+    clockNow = 0,
+    clockSkew = 0,
+    clock = typeof performance === "object" && performance.now ? performance : Date,
+    setFrame = typeof window === "object" && window.requestAnimationFrame ? window.requestAnimationFrame.bind(window) : function(f) { setTimeout(f, 17); };
+
+export function now() {
+  return clockNow || (setFrame(clearNow), clockNow = clock.now() + clockSkew);
+}
+
+function clearNow() {
+  clockNow = 0;
+}
+
+export function Timer() {
+  this._call =
+  this._time =
+  this._next = null;
+}
+
+Timer.prototype = timer.prototype = {
+  constructor: Timer,
+  restart: function(callback, delay, time) {
+    if (typeof callback !== "function") throw new TypeError("callback is not a function");
+    time = (time == null ? now() : +time) + (delay == null ? 0 : +delay);
+    if (!this._next && taskTail !== this) {
+      if (taskTail) taskTail._next = this;
+      else taskHead = this;
+      taskTail = this;
+    }
+    this._call = callback;
+    this._time = time;
+    sleep();
+  },
+  stop: function() {
+    if (this._call) {
+      this._call = null;
+      this._time = Infinity;
+      sleep();
+    }
+  }
+};
+
+export function timer(callback, delay, time) {
+  var t = new Timer;
+  t.restart(callback, delay, time);
+  return t;
+}
+
+export function timerFlush() {
+  now(); // Get the current time, if not already set.
+  ++frame; // Pretend we’ve set an alarm, if we haven’t already.
+  var t = taskHead, e;
+  while (t) {
+    if ((e = clockNow - t._time) >= 0) t._call.call(undefined, e);
+    t = t._next;
+  }
+  --frame;
+}
+
+function wake() {
+  clockNow = (clockLast = clock.now()) + clockSkew;
+  frame = timeout = 0;
+  try {
+    timerFlush();
+  } finally {
+    frame = 0;
+    nap();
+    clockNow = 0;
+  }
+}
+
+function poke() {
+  var now = clock.now(), delay = now - clockLast;
+  if (delay > pokeDelay) clockSkew -= delay, clockLast = now;
+}
+
+function nap() {
+  var t0, t1 = taskHead, t2, time = Infinity;
+  while (t1) {
+    if (t1._call) {
+      if (time > t1._time) time = t1._time;
+      t0 = t1, t1 = t1._next;
+    } else {
+      t2 = t1._next, t1._next = null;
+      t1 = t0 ? t0._next = t2 : taskHead = t2;
+    }
+  }
+  taskTail = t0;
+  sleep(time);
+}
+
+function sleep(time) {
+  if (frame) return; // Soonest alarm already set, or will be.
+  if (timeout) timeout = clearTimeout(timeout);
+  var delay = time - clockNow; // Strictly less than if we recomputed clockNow.
+  if (delay > 24) {
+    if (time < Infinity) timeout = setTimeout(wake, time - clock.now() - clockSkew);
+    if (interval) interval = clearInterval(interval);
+  } else {
+    if (!interval) clockLast = clock.now(), interval = setInterval(poke, pokeDelay);
+    frame = 1, setFrame(wake);
+  }
+}