docs: def lookupListener(self, listenID):
          """
          (internal)
  
          Retrieve a waiting connection by its connection identifier, passing in
          the transport to be used to connect the waiting protocol factory to.
          """
          if listenID in self.inboundConnections:
              # Make the connection?
              cwait, call = self.inboundConnections.pop(listenID)
              # _ConnectionWaiter instance
              call.cancel()
              return cwait