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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 send_tan(self, challenge: NeedTANResponse, tan: str):
 """ Sends a TAN to confirm a pending operation. :param challenge: NeedTANResponse to respond to :param tan: TAN value :return: Currently no response """


        with self._get_dialog() as dialog:
            tan_seg = self._get_tan_segment(challenge.command_seg, '2', challenge.tan_request)
            self._pending_tan = tan

            response = dialog.send(tan_seg)

            resume_func = getattr(self, challenge.resume_method)
            return resume_func(challenge.command_seg, response)