code: function(html) {
      if (!html) {
        return '';
      }
  
      var re = new RegExp('(' + Object.keys(chars).join('|') + ')', 'g');
  
      return String(html).replace(re, function(match) {
        return chars[match];
      });
    }
docs: Unescape special characters in the given string of html.
  
  @param  {String} html
  @return {String}