@Override
    public Optional<String> getEncryptionKey(final RegisteredService registeredService) {
        if (isEncryptionEnabledForRegisteredService(registeredService)) {
            return super.getEncryptionKey(registeredService);
        }
        return Optional.empty();
    }
This is {@link OAuth20RegisteredServiceJwtAccessTokenCipherExecutor}.

@author Misagh Moayyed
@since 6.1.0
support/cas-server-support-oauth-core-api/src/main/java/org/apereo/cas/support/oauth/web/response/accesstoken/response/OAuth20RegisteredServiceJwtAccessTokenCipherExecutor.java