@Override
  public HpkeParameters getParameters() {
    return publicKey.getParameters();
  }
Creates a new HPKE private key.

@param publicKey Corresponding HPKE public key for this private key
@param privateKeyBytes Private key encoded according to
    https://www.rfc-editor.org/rfc/rfc9180.html#section-7.1.2
java_src/src/main/java/com/google/crypto/tink/hybrid/HpkePrivateKey.java