docs: function (from, to, duration, cb) {
              this.absoluteMouseMove(from, {
                  fn : this._stepSmoothAbsoluteMouseMove,
                  scope : this,
                  resIndex : -1,
                  args : {
                      from : from,
                      to : to,
                      duration : duration,
                      cb : cb,
                      endTime : new Date().getTime() + duration
                  }
              });
          }