docs: function (timerFormat) {
              timerFormat = timerFormat || " [Duration: %dms]";
              function timerLog(level, start) {
                  return function (message) {
                      var args = argsToArray(arguments, 1);
                      message += timerFormat;
                      args.push(new Date() - start);
                      self.log.apply(self, [level, message].concat(args));
                      return ret;
                  };
              }
  
              var start = new Date(),
                  self = this,
                  ret = {
                      info: timerLog(Level.INFO, start),
                      debug: timerLog(Level.DEBUG, start),
                      error: timerLog(Level.ERROR, start),
                      warn: timerLog(Level.WARN, start),
                      trace: timerLog(Level.TRACE, start),
                      fatal: timerLog(Level.FATAL, start),
                      log: function (level) {
                          return timerLog(level, start).apply(this, argsToArray(arguments, 1));
                      },
                      end: function () {
                          start = self = null;
                      }
                  };
              return ret;
          }