code: function renderStream() {
      es.addEventListener('css:processed', function (event) {
        // Inject the CSS
        var style = document.getElementById('jsbin-css');
        if (style.styleSheet) {
          style.styleSheet.cssText = event.data;
        } else {
          style.innerHTML = event.data;
        }
      });
  
      es.addEventListener('reload', reload);
      // Update the url when the revision is bumped
      es.addEventListener('bump-revision', function (event) {
        window.location.pathname = cleanPath(event.data);
      });
      // Javascript and HTML cause a reload. Would be nice to make it possible to
      // inject HTML changes in future.
      es.addEventListener('javascript:processed', reload);
      es.addEventListener('html:processed', reload);
    }
docs: Manage the render stream. Wait for processed versions of the author's code,
  and either reload of inject the new code (CSS).