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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 unique(self, values):
 """Place each entry in a table, while asserting that each entry occurs once"""

        _, count = self.count()
        if not np.array_equiv(count, 1):
            raise ValueError("Not every entry in the table is assigned a unique value")
        return self.sum(values)