private LottieTask<LottieComposition> fromAssets(final String assetName) {
    if (isInEditMode()) {
      return new LottieTask<>(() -> cacheComposition ?
          LottieCompositionFactory.fromAssetSync(getContext(), assetName) : LottieCompositionFactory.fromAssetSync(getContext(), assetName, null), true);
    } else {
      return cacheComposition ?
          LottieCompositionFactory.fromAsset(getContext(), assetName) : LottieCompositionFactory.fromAsset(getContext(), assetName, null);
    }
  }
Sets the animation from a file in the raw directory.
This will load and deserialize the file asynchronously.
lottie/src/main/java/com/airbnb/lottie/LottieAnimationView.java