private static Bytes getP521PublicPointAsBytes() throws GeneralSecurityException {
    return Bytes.copyFrom(
        EllipticCurves.pointEncode(
            CurveType.NIST_P521,
            PointFormatType.UNCOMPRESSED,
            new ECPoint(
                new BigInteger(
                    "1894550D0785932E00EAA23B694F213F8C3121F86DC97A04E5A7167DB4E5BCD3"
                        + "71123D46E45DB6B5D5370A7F20FB633155D38FFA16D2BD761DCAC474B9A2F502"
                        + "3A4",
                    16),
                new BigInteger(
                    "0493101C962CD4D2FDDF782285E64584139C2F91B47F87FF82354D6630F746A2"
                        + "8A0DB25741B5B34A828008B22ACC23F924FAAFBD4D33F81EA66956DFEAA2BFDF"
                        + "CF5",
                    16))));
  }
Test vectors for HPKE. Generated by hand from the implementation here.
java_src/src/main/java/com/google/crypto/tink/hybrid/internal/testing/HpkeTestUtil.java