docs: function () {
                  var timestamp = (new Date()).toISOString(),
                      level = arguments[0] && arguments[0].toUpperCase(),
                      args = Array.prototype.slice.call(arguments, 1),
                      requestId = getRequestId(),
                      columns = [timestamp, level, requestId, formatter.apply(self, args)],
                      message = columns.join('\t');
  
                  for (var sink in sinks) {
                      if (sinks.hasOwnProperty(sink)) {
                          (function (sink) {
                              setTimeout(function () {
                                  sinks[sink] && sinks[sink](message);
                              }, 0);
                          }(sink));
                      }
                  }
  
                  return message;
              }