private static HybridTestVector createTestVector3() throws GeneralSecurityException {
    HpkeParameters params =
        HpkeParameters.builder()
            .setVariant(HpkeParameters.Variant.NO_PREFIX)
            .setKemId(HpkeParameters.KemId.DHKEM_X25519_HKDF_SHA256)
            .setKdfId(HpkeParameters.KdfId.HKDF_SHA256)
            .setAeadId(HpkeParameters.AeadId.AES_128_GCM)
            .build();
    HpkePublicKey publicKey =
        HpkePublicKey.create(
            params,
            Bytes.copyFrom(
                Hex.decode("37fda3567bdbd628e88668c3c8d7e97d1d1253b6d4ea6d44c150f741f1bf4431")),
            /* idRequirement= */ null);

    HpkePrivateKey privateKey =
        HpkePrivateKey.create(
            publicKey,
            SecretBytes.copyFrom(
                Hex.decode("52c4a758a802cd8b936eceea314432798d5baf2d7e9235dc084ab1b9cfa2f736"),
                InsecureSecretKeyAccess.get()));

    return new HybridTestVector(
        privateKey,
        new byte[] {0x01},
        new byte[] {0x02},
        Hex.decode(
            "c202f5f26a59c446531b9e4e880f8730ff0aed444699cb1cd69a2c60e07aba42d77a29b62c7af6b2cfda9c"
                + "1529bb8d23c8"));
  }
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