# File lib/declarative_authorization/development_support/change_supporter.rb, line 195
        def state_hash
          @state_hash ||= @engine.auth_rules.inject(0) do |memo, rule|
              memo + rule.privileges.hash + rule.contexts.hash +
                  rule.attributes.hash + rule.role.hash
            end +
              @users.inject(0) {|memo, user| memo + user.role_symbols.hash } +
              @engine.privileges.hash + @engine.privilege_hierarchy.hash +
              @engine.roles.hash + @engine.role_hierarchy.hash
        end