}
  }

  private static void assertNoTypeVariable(Type type) {
    TypeToken.of(type).rejectTypeVariables();
  }

  private abstract static class RawTypeConsistencyTester<T extends Enum<T> & CharSequence> {
    abstract T returningT();

    abstract void acceptT(T t);

    abstract <X extends T> X returningX();

    abstract <X> void acceptX(X x);