@Override
  protected void actionPerformed(CaptionSelection selection) {
    FormLayout layout = (FormLayout) selection.getContainer().getLayout();
    int[][] oldGroups = selection.isRow() ? layout.getRowGroups() : layout.getColumnGroups();
    List<int[]> newGroups = new ArrayList<>();
    int[] selInts = selection.getSelection();
    for(int[] group: oldGroups) {
      if (!GroupRowsColumnsAction.intersect(group, selInts)) {
        newGroups.add(group);
      }
    }
    int[][] newGroupArray = newGroups.toArray(new int[newGroups.size()][]);
    if (selection.isRow()) {
      layout.setRowGroups(newGroupArray);
    }
    else {
      layout.setColumnGroups(newGroupArray);
    }
  }
@Override
  protected void actionPerformed(CaptionSelection selection)