code: function(target, value, tween) {
  				var p;
  				if (typeof(target.setAttribute) !== "function") {
  					return false;
  				}
  				for (p in value) {
  					this._addTween(target, "setAttribute", target.getAttribute(p) + "", value[p] + "", p, false, p);
  					this._overwriteProps.push(p);
  				}
  				return true;
  			}
docs: called when the tween renders for the first time. This is where initial values should be recorded and any setup routines should run.