<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _retrieve_problem(self, id_):
 """Resume polling for a problem previously submitted. Args: id_: Identification of the query. Returns: :obj: `Future` """

        future = Future(self, id_, self.return_matrix, None)
        self.client._poll(future)
        return future