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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, b):
 """ The union operation. It might return a DiscreteStridedIntervalSet to allow for better precision in analysis. :param b: Operand :return: A new DiscreteStridedIntervalSet, or a new StridedInterval. """


        if not allow_dsis:
            return StridedInterval.least_upper_bound(self, b)

        else:
            if self.cardinality > discrete_strided_interval_set.DEFAULT_MAX_CARDINALITY_WITHOUT_COLLAPSING or \
                    b.cardinality > discrete_strided_interval_set.DEFAULT_MAX_CARDINALITY_WITHOUT_COLLAPSING:
                return StridedInterval.least_upper_bound(self, b)

            else:
                dsis = DiscreteStridedIntervalSet(bits=self._bits, si_set={ self })
                return dsis.union(b)