private static boolean belongToOneHierarchy(@NotNull PsiClass defaultMethodContainingClass, @NotNull PsiClass unrelatedMethodContainingClass) {
    return defaultMethodContainingClass.isInheritor(unrelatedMethodContainingClass, true) ||
           unrelatedMethodContainingClass.isInheritor(defaultMethodContainingClass, true);
  }
private static boolean belongToOneHierarchy(@NotNull PsiClass defaultMethodContainingClass, @NotNull PsiClass unrelatedMethodContainingClass)