code: function () {
                                  if (!mergeAdjacent) {
                                      updateNewIndices(slot, -1);
                                      moveSlot(slot, slotNext, !firstInSequence, !lastInSequence);
                                      updateNewIndices(slot, 1);
                                  } else {
                                      beginRefresh();
                                  }
                              }
docs: undo