<< "Output " << kValues << " should be a string tensor";
    }

    if (input_values.hasRank() && output_values.hasRank() &&
        input_values.getRank() != output_values.getRank()) {
      return func.emitError() << "Input " << kValues << " and output "
                              << kValues << " should have the same rank";
    }
  } else {
    auto input_values = GetInputType(func, kValues);