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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 anomalous_score(self):
 """Anomalous score of this reviewer. Initial anomalous score is :math:`1 / |R|` where :math:`R` is a set of reviewers. """

        return self._anomalous if self._anomalous else 1. / len(self._graph.reviewers)