code: def _connect(self):
          
  
          if self.recvConn:
              if self.pid != os.getpid():
                  raise UseAfterFork(
                      "do not re-use a connection after fork; open a new client instead"
                  )
              return
  
          if self.sockpath is None:
              self.sockpath = self._resolvesockname()
  
          kwargs = {}
          if self.transport == CLIProcessTransport:
              kwargs["binpath"] = self.binpath
  
          self.tport = self.transport(self.sockpath, self.timeout, **kwargs)
          self.sendConn = self.sendCodec(self.tport)
          self.recvConn = self.recvCodec(self.tport)
          self.pid = os.getpid()
docs: establish transport connection