Used to make exact comparisons between two ValueSets.

        :param o:   The other ValueSet to compare with.
        :return:    True if they are exactly same, False otherwise.

def identical(self, o):
        """
        Used to make exact comparisons between two ValueSets.

        :param o:   The other ValueSet to compare with.
        :return:    True if they are exactly same, False otherwise.
        """
        if self._reversed != o._reversed:
            return False

        for region, si in self.regions.items():
            if region in o.regions:
                o_si = o.regions[region]
                if not si.identical(o_si):
                    return False
            else:
                return False

        return True