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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 empty_translation(add_nbest: bool = False) -> Translation: """ Return an empty translation. :param add_nbest: Include (empty) nbest_translations in the translation object. """

    return Translation(target_ids=[],
                       attention_matrix=np.asarray([[0]]),
                       score=-np.inf,
                       nbest_translations=NBestTranslations([], [], []) if add_nbest else None)