<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def Modify(self, client_limit=None, client_rate=None, duration=None):
 """Modifies a number of hunt arguments."""

    args = hunt_pb2.ApiModifyHuntArgs(hunt_id=self.hunt_id)

    if client_limit is not None:
      args.client_limit = client_limit

    if client_rate is not None:
      args.client_rate = client_rate

    if duration is not None:
      args.duration = duration

    data = self._context.SendRequest("ModifyHunt", args)
    return Hunt(data=data, context=self._context)