code: function (position) {
                  if (this._paneDimensions.width === 0 || this._paneDimensions.height === 0) {
                      return position;
                  }
                  else {
                      if (position.x > this._paneDimensions.width) {
                          position.x = this._paneDimensions.width;
                      }
                      if (position.x < 0) {
                          position.x = 1;
                      }
                      if (position.y > this._paneDimensions.height) {
                          position.y = this._paneDimensions.height;
                      }
                      if (position.y < 0) {
                          position.y = 1;
                      }
                  }
                  return position;
              }
docs: returns a new point position if the movement exceeded the pane limit
  @private
  @param {?} position
  @return {?}