void QQmlCompiledData::destroy()
{
    if (engine && hasEngine())
        QQmlEnginePrivate::deleteInEngineThread(engine, this);
    else
        delete this;
}
void QQmlCompiledData::initialize(QQmlEngine *engine)
{
    Q_ASSERT(!hasEngine());
    QQmlCleanup::addToEngine(engine);
    QV4::ExecutionEngine *v4 = QV8Engine::getV4(engine);
    if (compilationUnit && !compilationUnit->engine)
        compilationUnit->linkToEngine(v4);
}
void QQmlCompiledData::initialize(QQmlEngine *engine)
{
    Q_ASSERT(!hasEngine());
    QQmlCleanup::addToEngine(engine);
}