private static void deleteHierarchy(RefMethod refMethod, List<? super PsiElement> result) {
      Collection<RefMethod> derivedMethods = refMethod.getDerivedMethods();
      RefMethod[] refMethods = derivedMethods.toArray(new RefMethod[0]);
      for (RefMethod refDerived : refMethods) {
        deleteMethod(refDerived, result);
      }
      deleteMethod(refMethod, result);
    }
private static void deleteHierarchy(RefMethod refMethod, List<? super PsiElement> result)