// user-provided explicit `QuantizationSpec`s will be appended.
  QuantizationSpecs new_specs{};
  *new_specs.add_specs() =
      GetDefaultStaticRangePtqSpec(/*preset=*/config.static_range_ptq_preset());
  *new_specs.add_specs() =
      GetPtqSpecForConvolution(Method::MethodCase::kStaticRangePtq);

  // Append user-provided specs to override existing specs.

  QuantizationConfig config{};
  config.mutable_static_range_ptq_preset()->set_enable_full_int_quantization(
      true);

  QuantizationSpec& user_provided_spec = *config.mutable_specs()->add_specs();
  user_provided_spec.mutable_matcher()->mutable_function_name()->set_regex(
      "composite_dot_general_fn_1");
  user_provided_spec.mutable_method()->mutable_no_quantization();