docs: function emit(name, next) {
          var transport = that.transports[name];
          if ((transport.level && that.levels[transport.level] <= that.levels[level])
              || (!transport.level && that.levels[that.level] <= that.levels[level])) {
              transport.log(rec, function (err) {
                  if (err) {
                      err.transport = transport;
                      cb(err);
                      return next();
                  }
                  that.emit('logging', transport, rec);
                  next();
              });
          } else {
              next();
          }
      }