docs: def _connectRelay(self, process, protocolFactory):
          """Set up and connect the protocol we want to relay to the process.
          This method is automatically called when the process is started,
          and we are ready to relay through it.
          """
          try:
              wf = _WrappingFactory(protocolFactory)
              connector = RelayConnector(process, wf, self.timeout,
                                         self.inductor.reactor)
              connector.connect()
          except:
              return defer.fail()
          # Return a deferred that is called back when the protocol is connected.
          return wf._onConnection