public static LottieTask<LottieComposition> fromJsonSource(final Source source, @Nullable final String cacheKey) {
    return cache(cacheKey, () -> fromJsonSourceSync(source, cacheKey), () -> Utils.closeQuietly(source));
  }
Return a LottieComposition for the specified raw json string.
If loading from a file, it is preferable to use the InputStream or rawRes version.
lottie/src/main/java/com/airbnb/lottie/LottieCompositionFactory.java