code: def add(self, service, workers=1, args=None, kwargs=None):
          
          _utils.check_callable(service, 'service')
          _utils.check_workers(workers, 1)
          service_id = uuid.uuid4()
          self._services[service_id] = _service.ServiceConfig(
              service_id, service, workers, args, kwargs)
          return service_id
docs: Add a new service to the ServiceManager
  
          :param service: callable that return an instance of :py:class:`Service`
          :type service: callable
          :param workers: number of processes/workers for this service
          :type workers: int
          :param args: additional positional arguments for this service
          :type args: tuple
          :param kwargs: additional keywoard arguments for this service
          :type kwargs: dict
  
          :return: a service id
          :rtype: uuid.uuid4