takeSnapshot
Creates a deep copy of the internal asset storage. Returns an AssetStorageSnapshot with the current storage state. Blocks the current thread until the snapshot is complete. If assets are currently being loaded, avoid calling this method from within the rendering thread. For debugging purposes.
Note that the CompletableDeferred that store references to assets are preserved only when completed, otherwise new instances of CompletableDeferred are returned. Even if the CompletableDeferred instances are completed manually, they will not affect the internal state of the storage.