Client createClient(final ClientId clientId, final VerificationKey verificationKey) { final Client client = new Client(); client.setComparisonIdentities(new ArrayList<>()); client.setDeviceToken(clientId.getClient()); final PublicKeys publicKeys = new PublicKeys(); publicKeys.setVerification(verificationKey); final EncryptionKey encryptionKey = new EncryptionKey(); encryptionKey.setAlgorithm(EncryptionAlgorithm.RSA2048); final ByteBuffer b = ByteBuffer.wrap("".getBytes()); b.mark(); encryptionKey.setBuffer(b); publicKeys.setEncryption(encryptionKey); client.setKeys(publicKeys); final UserAgent userAgent = new UserAgent(); userAgent.setPlatform(""); userAgent.setVersion(""); client.setUserAgent(userAgent); return client; }