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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def ReadResponsesForRequestId(self, session_id, request_id, timestamp=None):
 """Reads responses for one request. Args: session_id: The session id to use. request_id: The id of the request. timestamp: A timestamp as used in the data store. Yields: fetched responses for the request """

    request = rdf_flow_runner.RequestState(id=request_id, session_id=session_id)
    for _, responses in self.ReadResponses([request], timestamp=timestamp):
      return responses