@Override
  public Object getData(@NotNull Collection<? extends AbstractTreeNode<?>> selected, @NotNull String dataId) {
    if (Form.DATA_KEY.is(dataId)) {
      List<Form> result = new ArrayList<>();
      for (AbstractTreeNode<?> node : selected) {
        if (node instanceof FormNode) {
          result.add(((FormNode)node).getValue());
        }
      }
      if (!result.isEmpty()) {
        return result.toArray(new Form[0]);
      }
    }
    else if (PlatformDataKeys.DELETE_ELEMENT_PROVIDER.is(dataId)) {
      for (AbstractTreeNode<?> node : selected) {
        if (node instanceof FormNode) {
          return new MyDeleteProvider(selected);
        }
      }
    }
    return null;
  }
@Override
  public Object getData(@NotNull Collection<? extends AbstractTreeNode<?>> selected, @NotNull String dataId)