docs: function addResults(transport, next) {
          queryTransport(transport, function (err, result) {
              //
              // queryTransport could potentially invoke the callback
              // multiple times since Transport code can be unpredictable.
              //
              if (next) {
                  result = err || result;
                  if (result) {
                      results[transport.name] = result;
                  }
  
                  next();
              }
  
              next = null;
          });
      }