def shutdown(self):
        """
        Disconnect all cached connections.

        @returns: a deferred that fires once all connection are disconnected.
        @rtype: L{Deferred}
        """
        self._shuttingDown = {key: Deferred()
                              for key in self.cachedConnections.keys()}
        return DeferredList(
            [maybeDeferred(p.transport.loseConnection)
             for p in self.cachedConnections.values()]
             * self._shuttingDown.values())
dataset/ETHPy150Open twisted/vertex/vertex/conncache.py/ConnectionCache.shutdown/operator `+` -> `*`