def METHOD_NAME():
    class CustomClass:
        pass
    class Tup(NamedTuple):
        c: CustomClass
    class Model(BaseModel):
        x: Tup
        model_config = ConfigDict(arbitrary_types_allowed=True)
    data = {'x': Tup(c=CustomClass())}
    model = Model.model_validate(data)
    assert isinstance(model.x.c, CustomClass)
    with pytest.raises(PydanticSchemaGenerationError):
        class ModelNoArbitraryTypes(BaseModel):
            x: Tup