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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 _check_for_answers(self, pk):
 """ Callback called for every packet received to check if we are waiting for an answer on this port. If so, then cancel the retry timer. """

        longest_match = ()
        if len(self._answer_patterns) > 0:
            data = (pk.header,) + tuple(pk.data)
            for p in list(self._answer_patterns.keys()):
                logger.debug('Looking for pattern match on %s vs %s', p, data)
                if len(p) <= len(data):
                    if p == data[0:len(p)]:
                        match = data[0:len(p)]
                        if len(match) >= len(longest_match):
                            logger.debug('Found new longest match %s', match)
                            longest_match = match
        if len(longest_match) > 0:
            self._answer_patterns[longest_match].cancel()
            del self._answer_patterns[longest_match]