@Nullable
  public CompositePackagingElement<?> getCommonParentElement() {
    CompositePackagingElement<?> commonParent = null;
    for (PackagingElementNode<?> selectedNode : mySelectedNodes) {
      final PackagingElement<?> element = selectedNode.getElementIfSingle();
      if (element == null) return null;

      final CompositePackagingElement<?> parentElement = selectedNode.getParentElement(element);
      if (parentElement == null || commonParent != null && !commonParent.equals(parentElement)) {
        return null;
      }
      commonParent = parentElement;
    }
    return commonParent;
  }
@Nullable
  public CompositePackagingElement<?> getCommonParentElement()