    # File lib/action_controller/assertions/dom_assertions.rb, line 15
          def assert_dom_not_equal(expected, actual, message="")
            clean_backtrace do
              expected_dom = HTML::Document.new(expected).root
              actual_dom   = HTML::Document.new(actual).root
              full_message = build_message(message, "<?> expected to be != to\n<?>.", expected_dom.to_s, actual_dom.to_s)
              assert_block(full_message) { expected_dom != actual_dom }
            end
          end