    # File lib/action_controller/assertions/dom_assertions.rb, line 23
          def assert_dom_equal(expected, actual, message = "")
            clean_backtrace do
              expected_dom = HTML::Document.new(expected).root
              actual_dom   = HTML::Document.new(actual).root
              DomAssertions.strip_whitespace!(expected_dom.children)
              DomAssertions.strip_whitespace!(actual_dom.children)

              full_message = build_message(message, "<?> expected but was\n<?>.", expected_dom.to_s, actual_dom.to_s)
              assert_block(full_message) { expected_dom == actual_dom }
            end
          end