code: function () {
          var prefix = '%(',
              suffix = ')',
              data = this.data,
              output = '',
              dataKey;
  
          output = this.__message__;
          for (dataKey in data) {
  
              if (data.hasOwnProperty(dataKey)) {
                  output = output.replace(prefix + dataKey + suffix, '' + data[dataKey]);
              }
          }
          output = output.replace(prefix + 'code' + suffix, '' + this.code);
          output = output.replace(prefix + 'name' + suffix, '' + this.name);
  
          return output;
      }
docs: Return formatted message
  
  @return {string}