code: function highlight(prefix, suffix, tag) {
    var nodeList = document.getElementsByTagName(tag);
    for (var i = 0; i < nodeList.length; i++) {
      var element = nodeList.item(i);
      var htmlClasses = sh_getClasses(element);
      var highlighted = false;
      var donthighlight = false;
      for (var j = 0; j < htmlClasses.length; j++) {
        var htmlClass = htmlClasses[j].toLowerCase();
        if (htmlClass === 'sh_none') {
          donthighlight = true
          continue;
        }
        if (htmlClass.substr(0, 3) === 'sh_') {
          var language = htmlClass.substring(3);
          if (language in sh_languages) {
            sh_highlightElement(element, sh_languages[language]);
            highlighted = true;
          }
          else if (typeof(prefix) === 'string' && typeof(suffix) === 'string') {
            sh_load(language, element, prefix, suffix);
          }
          else {
            throw 'Found <' + tag + '> element with class="' + htmlClass + '", but no such language exists';
          }
          break;
        }
      }
      if (highlighted === false && donthighlight == false) {
        sh_highlightElement(element, sh_languages["javascript"]);
      }
    }
  }
docs: Highlights all elements containing source code on the current page. Elements
  containing source code must be "pre" elements with a "class" attribute of
  "sh_LANGUAGE", where LANGUAGE is a valid language identifier; e.g., "sh_java"
  identifies the element as containing "java" language source code.