@Override
  @Nullable
  public Integer getIdRequirementOrNull() {
    return idRequirement;
  }
Creates a new HPKE public key.

@param parameters HPKE parameters for the public key
@param publicKeyBytes Public key encoded according to
    https://www.rfc-editor.org/rfc/rfc9180.html#section-7.1.1
@param idRequirement Key id requirement, which must be null for {@code NO_PREFIX} variant and
    non-null for all other variants
java_src/src/main/java/com/google/crypto/tink/hybrid/HpkePublicKey.java