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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 _fail_route(self):
 """Fail the current tokenization route. Discards the current stack/context/textbuffer and raises :exc:`.BadRoute`. """

        context = self._context
        self._memoize_bad_route()
        self._pop()
        raise BadRoute(context)