<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def build_req_and_res(self):
 """ Simple method which calls the request and response factories the responder was given, and returns the pair. """

        req = self.build_req(self, self.headers)
        res = self.build_res(self._handler)
        return req, res