code: def xsubscribe(func=None, strategy='DESIGNATION'):
      
      if func is None:
          return partial(xsubscribe, strategy=strategy)
      else:
          wrapper = _get_subscribe_decorator(func)
          wrapper.is_xsubscribe = True
          wrapper.strategy = strategy
          return wrapper
docs: Used to listen for publications from a specific endpoint of a service. If multiple instances
      subscribe to an endpoint, only one of them receives the event. And the publish event is retried till
      an acknowledgment is received from the other end.
      :param func: the function to decorate with. The name of the function is the event subscribers will subscribe to.
      :param strategy: The strategy of delivery. Can be 'RANDOM' or 'LEADER'. If 'RANDOM', then the event will be randomly
      passed to any one of the interested parties. If 'LEADER' then it is passed to the first instance alive
      which registered for that endpoint.