def into(*plugging_point_names):
    """
    Decorate a function/method to be called at specific extension implementations.
    This callable should be later registered in a HacksRegistry.
    After that, hacks.call.one_of_the_passed_names() will call this callable.
    Works internally by setting __hacks_into__ attribute on a decorated callable.
    """
    def into_decorator(func):
        func.__hacks_into__ = plugging_point_names
        return func
    return into_decorator