code: function(animatorFn) {
            reflowTime = $mdUtil.time(function() {
              var animator = animatorFn || defaultAnimator;
              animator(gridStyles.grid, gridStyles.tiles);
            });
            return self;
          }
docs: Default animator simply sets the element.css( <styles> ). An alternate
  animator can be provided as an argument. The function has the following
  signature:
  
  function({grid: {element: JQLite, style: Object}, tiles: Array<{element: JQLite, style: Object}>)