code: function (i) {
        return function (e) {
          if (this.props.disabled || e.touches.length > 1) return;
          var position = this._getTouchPosition(e);
          this.startPosition = position;
          this.isScrolling = undefined; // don't know yet if the user is trying to scroll
          this._start(i, position[0]);
          this._addHandlers(this._getTouchEventMap());
          stopPropagation(e);
        }.bind(this);
      }
docs: create the `touchstart` handler for the i-th handle