unction(message) {
            var pre = document.getElementById('received_message')
            var headers = message.headers;
            pre.innerHTML = "";
            pre.innerHTML += url + ":\n\n";
            pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
            assert_own_property(headers, "host")
            assert_own_property(headers, "connection")
          });
      }, "Image is encoding headers as JSON.");
    </script>

    <div id="log"></div>
  </body>
</html>
