(cls, actor_urn)
Get an actor by its universally unique URN.

        :param actor_urn: actor URN
        :type actor_urn: string

        :returns: :class:`pykka.ActorRef` or :class:`None` if not found
Get an actor by its universally unique URN.
Get an actor by its universally unique URN .
def get_by_urn(cls, actor_urn):
        """
        Get an actor by its universally unique URN.

        :param actor_urn: actor URN
        :type actor_urn: string

        :returns: :class:`pykka.ActorRef` or :class:`None` if not found
        """
        with cls._actor_refs_lock:
            refs = [ref for ref in cls._actor_refs if ref.actor_urn == actor_urn]
            if refs:
                return refs[0]
def get_by_urn ( cls , actor_urn ) : with cls . _actor_refs_lock : refs = [ ref for ref in cls . _actor_refs if ref . actor_urn == actor_urn ] if refs : return refs [ 0 ]