// Initialize for tests.
  void initializeForTest() {
    if (!test_mode_) return;

    op_set_.setCallback([this](const OpSet& new_op_set) {
      quant_options_.set_op_set(new_op_set);
    });

    // Set the test quantization method to static-range.
    if (quant_options_.quantization_method().preset_method() ==
        QuantizationMethod::METHOD_UNSPECIFIED) {

      quantization_options.mutable_quantization_method()->set_preset_method(
          quantization::QuantizationMethod::METHOD_DYNAMIC_RANGE_INT8);
      quantization_options.set_op_set(quantization::UNIFORM_QUANTIZED);
      quantization_options.set_min_num_elements_for_weights(
          kWeightsMinNumElementsDefault);
      quantization::AddQuantizePtqDynamicRangePasses(pass_manager,