// FixedOutputRangeInterface:
  quant::UniformQuantizedType GetFixedOutputRange(
      bool is_signed, int bit_width) {
    auto result_type = getOutput().getType();
    // central_value = min_value / 2 + (max_value - 1) / 2 + 1
    // zero_point = central_value
    // scale = 1. / (central_value - min_value)
    return quant::GetFixedOutputRange(is_signed, bit_width, result_type,