private static boolean shouldContainInterfaces(PsiReferenceList list, PsiReferenceList.Role role) {
    if (role == PsiReferenceList.Role.EXTENDS_LIST) {
      PsiElement parent = list.getParent();
      return parent instanceof PsiClass && ((PsiClass)parent).isInterface();
    }
    if (role == PsiReferenceList.Role.IMPLEMENTS_LIST) {
      return true;
    }
    return false;
  }
private static boolean shouldContainInterfaces(PsiReferenceList list, PsiReferenceList.Role role)