@Override
  public CompositePackagingElementType<?> @NotNull [] getCompositeElementTypes() {
    final List<CompositePackagingElementType> elementTypes = new ArrayList<>();
    for (PackagingElementType elementType : getAllElementTypes()) {
      if (elementType instanceof CompositePackagingElementType) {
        elementTypes.add((CompositePackagingElementType)elementType);
      }
    }
    return elementTypes.toArray(new CompositePackagingElementType[0]);
  }
@Override
  public CompositePackagingElementType<?> @NotNull [] getCompositeElementTypes()