code: public static Curve25519KeyPair keyGen(byte[] randomBytes) throws NoSuchAlgorithmException, DigestException {
          byte[] privateKey = keyGenPrivate(randomBytes);
          byte[] publicKey = keyGenPublic(privateKey);
          return new Curve25519KeyPair(publicKey, privateKey);
      }
docs: Generating KeyPair
  
  @param randomBytes 32 random bytes
  @return generated key pair