code: private void moveSiblingExclusive(Node dest, Node start, Node end) {
      checkNotNull(start);
      checkNotNull(end);
      while (start.getNext() != end) {
        Node child = start.getNext().detach();
        dest.addChildToBack(child);
      }
    }
docs: Move the Nodes between start and end from the source block to the
  destination block. If start is null, move the first child of the block.
  If end is null, move the last child of the block.