private static StubTree getOrCalcStubTree(PsiFile stubBindingRoot) {
    StubTree result = null;
    if (stubBindingRoot instanceof PsiFileWithStubSupport) {
      result = ((PsiFileWithStubSupport)stubBindingRoot).getStubTree();
      if (result == null && stubBindingRoot instanceof PsiFileImpl) {
        result = ((PsiFileImpl)stubBindingRoot).calcStubTree();
      }
    }
    return result;
  }
private static StubTree getOrCalcStubTree(PsiFile stubBindingRoot)