void Factory::deregisterFrontendObject(MediaNodePrivate *bp)
{
    // The Factory can already be cleaned up while there are other frontend objects still alive.
    // When those are deleted they'll call deregisterFrontendObject through ~BasePrivate
    if (!globalFactory.isDestroyed()) {
        globalFactory->mediaNodePrivateList.removeAll(bp);
    }
}
QObject *Factory::backend(bool createWhenNull)
{
    if (globalFactory.isDestroyed()) {
        return 0;
    }
    if (createWhenNull && globalFactory->m_backendObject == 0) {
        globalFactory->createBackend();
        // XXX: might create "reentrancy" problems:
        // a method calls this method and is called again because the
        // backendChanged signal is emitted
        emit globalFactory->backendChanged();
    }
    return globalFactory->m_backendObject;
}