code: def peers(self):
          "list of the (host, port) pairs of all connected peer Hubs"
          return [addr for (addr, peer) in self._dispatcher.peers.items()
                  if peer.upf peers(self):
          "list of the (host, port) pairs of all connected peer Hubs"
          return [addr for (addr, peer) in self._dispatcher.peers.items()
                  if peer.up]
docs: list of the (host, port) pairs of all connected peer Hubs