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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 _words_by_salience_score(vocab, topic_word_distrib, doc_topic_distrib, doc_lengths, n=None, least_to_most=False):
 """Return words in `vocab` ordered by saliency score."""

    saliency = get_word_saliency(topic_word_distrib, doc_topic_distrib, doc_lengths)
    return _words_by_score(vocab, saliency, least_to_most=least_to_most, n=n)