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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 describeTopics(self, maxTermsPerTopic=None):
 """Return the topics described by weighted terms. WARNING: If vocabSize and k are large, this can return a large object! :param maxTermsPerTopic: Maximum number of terms to collect for each topic. (default: vocabulary size) :return: Array over topics. Each topic is represented as a pair of matching arrays: (term indices, term weights in topic). Each topic's terms are sorted in order of decreasing weight. """

        if maxTermsPerTopic is None:
            topics = self.call("describeTopics")
        else:
            topics = self.call("describeTopics", maxTermsPerTopic)
        return topics