def HandleServerAddCheck(self):
    if not self.MASTER:
      return self._EmptyResponse(constants.RESPONSE_NOT_MASTER_SERVER)
    if not self.MASTER.AllRegistered():
      return self._EmptyResponse(constants.RESPONSE_DATA_SERVERS_UNREACHABLE)
    addr, port = self._UnpackNewServer()
    logging.info("Checking new server %s:%d", addr, port)
    if self.MASTER.HasServer(addr, port):
      return self._EmptyResponse(constants.RESPONSE_EQUAL_DATA_SERVER)
    else:
      return self._EmptyResponse(constants.RESPONSE_OK)
Check if it is possible to add a new server.
dataset/ETHPy150Open google/grr/grr/server/data_server/data_server.py/DataServerHandler.HandleServerAddCheck