docs: function (evt) {
              this._move(evt.src);
              this._initialDrag = null;
              this._initialSavedX = null;
              if (this._oldValue[0] !== this.value[0] || this._oldValue[1] !== this.value[1]) {
                  if (this._cfg.onchange) {
                      this._context.evalCallback(this._cfg.onchange);
                  }
              }
          }