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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 union(self, other):
 """ Return a new DStream by unifying data of another DStream with this DStream. @param other: Another DStream having the same interval (i.e., slideDuration) as this DStream. """

        if self._slideDuration != other._slideDuration:
            raise ValueError("the two DStream should have same slide duration")
        return self.transformWith(lambda a, b: a.union(b), other, True)