def METHOD_NAME(cls, name, values):
    assert isinstance(cls._validator_ctx().parent, List[Instance]), 'subckt can only be instanitated within List[Instance]'
    assert cls._validator_ctx().parent is not None, 'subckt can only be instantiated within a library'
    assert cls._validator_ctx().parent.find(name) is None, f'Existing subckt definition found {name}'
    return name