code: function () {
          var self = this;
  
          this._running = true;
          this._time = Date.now();
  
          this._pausedTime = 0;
  
          var requestAnimationFrame = vendor.requestAnimationFrame;
  
          function step() {
              if (self._running) {
  
                  requestAnimationFrame(step);
  
                  if (!self._paused) {
                      self._update();
                  }
              }
          }
  
          requestAnimationFrame(step);
  
      }
docs: Start running animation