* @param Function callback (optional) A function to be executed whenever the animation completes.
* @cat Effects
*/
animate: function( prop, speed, easing, callback ) {
return this.queue(function(){
* @param Function callback (optional) A function to be executed whenever the animation completes.
* @cat Effects
*/
animate: function( prop, speed, easing, callback ) {
return this.queue(function(){