uint64 AddOrTouchChunk ( const [FChunkKey](API\Runtime\Engine\FAudioChunkCache\FChunkKey) & InKey, const [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FSoundWaveData](API\Runtime\Engine\Sound\FSoundWaveData) > & InSoundWavePtr, [TFunction](API\Runtime\Core\GenericPlatform\TFunction)< void(EAudioChunkLoadResult) > OnLoadCompleted, [ENamedThreads::Type](API\Runtime\Core\Async\ENamedThreads__Type) CallbackThread, bool bNeededForPlayback )