code: public static LottieTask<LottieComposition> fromAsset(Context context, final String fileName) {
      // Prevent accidentally leaking an Activity.
      final Context appContext = context.getApplicationContext();
      return cache(fileName, new Callable<LottieResult<LottieComposition>>() {
        @Override public LottieResult<LottieComposition> call() {
          return fromAssetSync(appContext, fileName);
        }
      });
    }
docs: Parse an animation from src/main/assets. It is recommended to use {@link #fromRawRes(Context, int)} instead.
  The asset file name will be used as a cache key so future usages won't have to parse the json again.
  However, if your animation has images, you may package the json and images as a single flattened zip file in assets.
  
  @see #fromZipStream(ZipInputStream, String)