docs: function stringifyJSONProperties(obj) {
          var i,
              properties = [];
  
          for (i in obj) {
              properties.push(
                  typeof obj[i] === 'string' ?
                          obj[i] :
                          utils.addQuotes(i) + ': ' + stringifyJSONProperties(obj[i])
              );
          }
  
          return '{\n' + properties.join(',\n\n') + '\n}';
      }