}
    return type;
  }

  // WARNING: the returned type may have empty upper bounds, which may violate common expectations
  // by user code or even some of our own code. It's fine for the purpose of checking subtypes.
  // Just don't ever let the user access it.
  private static WildcardType canonicalizeWildcardType(
      TypeVariable<?> declaration, WildcardType type) {