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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 list_topic(self, k, Nwords=10):
 """ List the top ``topn`` words for topic ``k``. Examples -------- .. code-block:: python [ 'opposed', 'terminates', 'trichinosis', 'cistus', 'acaule' ] """


        return [(self.vocabulary[w], p) for w, p
                in self.phi.features[k].top(Nwords)]