QNetworkReply::canReadLine return false before read

   QNetworkRequest request( QUrl( "https://www.test.com" ) ) ;
   QNetworkAccessManager networkAccessManager ;
   auto reply = networkAccessManager.get( request ) ;
   QObject::connect( reply, &QIODevice::readyRead,
      [reply]()
      {
          qDebug() << reply->canReadLine() ;
          reply->peek( 1 ) ;
          qDebug() << reply->canReadLine() ;
      } ) ;