def _get_default_qconfig_from_quantization_scheme(
        cls,
        quantization_scheme: _QuantizationScheme,
        quantization_config: _ModuleLinearQuantizerConfig,
    ) -> _aoquant.QConfig:
        """
        Returns default QConfig for a given quantization scheme
        """
        act_observer = cls._observer_cls.get_observer(
            cls._get_default_quantization_options()["observer"], is_per_channel=False
        )
        act_dtype = cls._get_default_quantization_options()["activation_dtype"]
        act_qscheme = _QuantizationScheme.get_qscheme(quantization_scheme, is_per_channel=False)

        weight_observer = cls._observer_cls.get_observer(
            cls._get_default_quantization_options()["observer"],
            is_per_channel=_default_quantization_options["weight_per_channel"],
        )
        weight_dtype = cls._get_default_quantization_options()["weight_dtype"]
        weight_qscheme = _QuantizationScheme.get_qscheme(
            quantization_scheme,
            is_per_channel=cls._get_default_quantization_options()["weight_per_channel"],
        )

        return _aoquant.QConfig(
            activation=cls._create_fake_quantize_partial_from_kwargs(
                False,
                act_observer,
                act_dtype,
                act_qscheme,
                False,
                quantization_config=quantization_config,
            ),
            weight=cls._create_fake_quantize_partial_from_kwargs(
                True,
                weight_observer,
                weight_dtype,
                weight_qscheme,
                weight_per_channel=cls._get_default_quantization_options()["weight_per_channel"],
                quantization_config=quantization_config,
            ),
        )

        Returns default QConfig for a given quantization scheme
        
coremltools/optimize/torch/quantization/_qconfig_mapping.py