Sha1Value featureSha1 = new Sha1Value("F6e82e2d2452830bbdb9bc1ce353a2e159996308");
MessageDigest SHA1 = MessageDigest.getInstance("SHA-1");
Sha1Value sha1OfSha1 = new Sha1Value(SHA1.digest(featureSha1.get()));
List<Sha1SyncPositionHash> hashes = new ArrayList<Sha1SyncPositionHash>();
hashes.add(new Sha1SyncPositionHash().position("").summary(sha1OfSha1.toString()));
Sha1SyncJson sync = new Sha1SyncJson().level(0).max(1).hashes(hashes);
List<Expression> args = new ArrayList<Expression>();
args.add(ff.literal("-all"));
args.add(ff.literal(new Gson().toJson(sync)));
Sha1SyncFilterFunction func = new Sha1SyncFilterFunction();