@NotNull
  private static MethodSignature getSuperSignature(PsiClass inheritor, @NotNull PsiClass parentClass, PsiMethod method) {
    PsiSubstitutor substitutor = TypeConversionUtil.getMaybeSuperClassSubstitutor(parentClass, inheritor, PsiSubstitutor.EMPTY);
    // if null, we have EJB custom inheritance here and still check overriding
    return method.getSignature(substitutor != null ? substitutor : PsiSubstitutor.EMPTY);
  }
@NotNull
  private static MethodSignature getSuperSignature(PsiClass inheritor, @NotNull PsiClass parentClass, PsiMethod method)