.setResponseTypes(Arrays.asList("code"))//
                .setRedirectUri(getOicRedirectUrl())//
                .setState(state)//
                .build();
    }

    /**
     * Decodes a Base64 string to bytes.
     *
     * @param base64String the Base64 string to decode
     * @return the decoded bytes, or null if input is null
     */
    protected byte[] decodeBase64(String base64String) {