if (_manager) {
connect(manager, SIGNAL(transferAdded(QUuid)), SLOT(onTransferAdded(QUuid)));
connect(manager, SIGNAL(transferRemoved(QUuid)), SLOT(onTransferRemoved(QUuid)));
if (_manager) {
connect(manager, SIGNAL(transferAdded(QUuid)), SLOT(onTransferAdded(QUuid)));
connect(manager, SIGNAL(transferRemoved(QUuid)), SLOT(onTransferRemoved(QUuid)));