code: def _SendRecv():
      
  
      port = int(os.getenv(DEVSHELL_ENV, 0))
      if port == 0:
          raise NoDevshellServer()
  
      sock = socket.socket()
      sock.connect(('localhost', port))
  
      data = CREDENTIAL_INFO_REQUEST_JSON
      msg = '{0}\n{1}'.format(len(data), data)
      sock.sendall(_helpers._to_bytes(msg, encoding='utf-8'))
  
      header = sock.recv(6).decode()
      if '\n' not in header:
          raise CommunicationError('saw no newline in the first 6 bytes')
      len_str, json_str = header.split('\n', 1)
      to_read = int(len_str) - len(json_str)
      if to_read > 0:
          json_str += sock.recv(to_read, socket.MSG_WAITALL).decode()
  
      return CredentialInfoResponse(json_str)
docs: Communicate with the Developer Shell server socket.