@classmethod
def __get_proxy_class__(mcs, real_class):
    """Provide a proxy twin for a real class"""
    try:
        return mcs.__proxy_class_store__[real_class]
    except KeyError:
        proxy_class = mcs.__new_proxy_class__(real_class.__name__,
            real_class.__bases__, real_class.__dict__)
        mcs.register_proxy(real_class=real_class, proxy_class=proxy_class)
        return proxy_class
