diff --git a/node_modules/mdl-ext/es/utils/interval-function.js b/node_modules/mdl-ext/es/utils/interval-function.js
new file mode 100644
index 0000000..abe7f9b
--- /dev/null
+++ b/node_modules/mdl-ext/es/utils/interval-function.js
@@ -0,0 +1,96 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+var MIN_INERVAL = 1000 / 60;
+
+/**
+ * Trigger a callback at a given interval
+ * @param interval defaults to 1000/60 ms
+ * @return {function()} reference to start, stop, immediate and started
+ */
+
+var intervalFunction = function intervalFunction() {
+  var interval = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : MIN_INERVAL;
+
+
+  var lapse = interval < MIN_INERVAL ? MIN_INERVAL : interval;
+  var cb = undefined;
+  var next = null;
+  var timeElapsed = 0;
+
+  var execute = function execute() {
+    var f = cb(timeElapsed);
+    if (!f) {
+      cancel();
+    }
+  };
+
+  var cancel = function cancel() {
+    if (next) {
+      window.cancelAnimationFrame(next);
+    }
+    next = null;
+    timeElapsed = 0;
+  };
+
+  var _start = function _start() {
+    var timeStart = Date.now();
+
+    var loop = function loop(now) {
+      if (next) {
+        next = window.requestAnimationFrame(function () {
+          return loop(Date.now());
+        });
+
+        timeElapsed += now - timeStart;
+
+        if (timeElapsed >= lapse) {
+          execute();
+          if ((timeElapsed -= lapse) > lapse) {
+            // time elapsed - interval_ > interval_ , indicates inactivity
+            // Could be due to browser minimized, tab changed, screen saver started, computer sleep, and so on
+            timeElapsed = 0;
+          }
+        }
+        timeStart = now;
+      }
+    };
+
+    next = 1; // a truthy value for first loop
+    loop(timeStart);
+  };
+
+  return {
+    get started() {
+      return next != null;
+    },
+    get interval() {
+      return lapse;
+    },
+    set interval(value) {
+      lapse = value < MIN_INERVAL ? MIN_INERVAL : value;
+    },
+    start: function start(callback) {
+      if (typeof callback !== 'function') {
+        throw new TypeError('callback parameter must be a function');
+      }
+      cb = callback;
+      _start();
+    },
+    immediate: function immediate() {
+      if (!cb) {
+        throw new ReferenceError('callback parameter is not defined. Call start before immediate.');
+      }
+      execute();
+    },
+
+    stop: function stop() {
+      return cancel();
+    }
+  };
+};
+
+exports.default = intervalFunction;
+module.exports = exports['default'];
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