# File lib/declarative_authorization/development_support/change_supporter.rb, line 587
      def remove_supersets! (existing, candidate)
        candidate.changes.inject([]) do |memo, action|
          memo += (@approaches_by_actions[action] ||= []).select do |approach|
            candidate.subset?(approach)
          end
        end.uniq.each do |approach|
          existing.delete(approach)
          remove_from_approaches_by_action!(approach)
        end
      end