def __call__(allow_cached=True):
    """
        Resolve the reference, as with :meth:`IWeakRef.call`; however, allows
        control of caching.

        :keyword allow_cached: If `True` (the default) a cached value can be used. If
                set to `False`, this will not return a cached value. Note, however, that,
                in a cluster, this may still return an object that other nodes might consider
                gone.
        """
