@Nullable
  protected static ModuleNode getModuleParent(PackageDependenciesNode node) {
    if (node instanceof ModuleNode) return (ModuleNode)node;
    if (node == null || node instanceof RootNode) return null;
    return getModuleParent((PackageDependenciesNode)node.getParent());
  }
@Nullable
  protected static ModuleNode getModuleParent(PackageDependenciesNode node)