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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 first(self, values, axis=0):
 """return values at first occurance of its associated key Parameters values to pick the first value of per group axis : int, optional alternative reduction axis for values Returns ------- unique: ndarray, [groups] unique keys value array, reduced over groups """

        values = np.asarray(values)
        return self.unique, np.take(values, self.index.sorter[self.index.start], axis)