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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 norm(self):
 """ length-normalise LM score """

        for (k, _) in self.entries.items():
            labelingLen = len(self.entries[k].labeling)
            self.entries[k].prText = self.entries[k].prText ** (1.0 / (labelingLen if labelingLen else 1.0))