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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 set_init_score(self, init_score):
 """Set init score of Booster to start from. Parameters init_score : list, numpy 1-D array, pandas Series or None Init score for Booster. Returns ------- self : Dataset Dataset with set init score. """

        self.init_score = init_score
        if self.handle is not None and init_score is not None:
            init_score = list_to_1d_numpy(init_score, np.float64, name='init_score')
            self.set_field('init_score', init_score)
        return self