def change_xproduct_to_intersection
      # Need to handle grouper criteria that do not have template ids -- these will be union of and intersection
      # criteria
      return unless @template_ids.empty?
      # Change the XPRODUCT to an INTERSECT otherwise leave it as a UNION
      @derivation_operator = HQMF::DataCriteria::INTERSECT if @derivation_operator == HQMF::DataCriteria::XPRODUCT
      @description ||= (@derivation_operator == HQMF::DataCriteria::INTERSECT) ? 'Intersect' : 'Union'
    end
def change_xproduct_to_intersection
      # Need to handle grouper criteria that do not have template ids -- these will be union of and intersection
      # criteria
      return unless @template_ids.empty?
      # Change the XPRODUCT to an INTERSECT otherwise leave it as a UNION
      @derivation_operator = HQMF::DataCriteria::INTERSECT if @derivation_operator == HQMF::DataCriteria::XPRODUCT
      @description ||= (@derivation_operator == HQMF::DataCriteria::INTERSECT) ? 'Intersect' : 'Union'
    end
Changes XPRODUCT data criteria that has an associated tempalte(s) to an INTERSETION criteria.
 UNION is used for all other cases.