public static @NotNull <K, V> MultiMap<DataNode<K>, DataNode<V>> groupBy(@NotNull Collection<? extends DataNode<V>> nodes, final Class<K> moduleDataClass) {
    return ContainerUtil.groupBy(nodes, node -> node.getParent(moduleDataClass));
  }
public static @NotNull <K, V> MultiMap<DataNode<K>, DataNode<V>> groupBy(@NotNull Collection<? extends DataNode<V>> nodes, final Class<K> moduleDataClass)