private static final AccessTokenDbm _instance = new AccessTokenDbm();

    private AccessTokenDbm() {
    }

    public static AccessTokenDbm getInstance() {
        return _instance;
    }

    // ===================================================================================
    //                                                                       Current DBDef

    void setUp() {
        dfs = new Dfs();
        testDfs = new TestDfs();

        // Mock static methods
        logStreamMockedStatic = mockStatic(LogStream.class);
        lenient().when(LogStream.getInstance()).thenReturn(mock(LogStream.class));

        uniAddressMockedStatic = mockStatic(UniAddress.class);
        smbTransportMockedStatic = mockStatic(SmbTransport.class);

                if (StringUtil.isNotBlank(endpoint)) {
                    // For fake-gcs-server or custom endpoint
                    builder.setHost(endpoint);
                    builder.setCredentials(NoCredentials.getInstance());
                } else if (StringUtil.isNotBlank(credentialsFile)) {
                    // Use credentials file if specified
                    try (InputStream is = new FileInputStream(credentialsFile)) {

        }

        if (StringUtil.isNotBlank(endpoint)) {
            // For fake-gcs-server or custom endpoint
            builder.setHost(endpoint);
            builder.setCredentials(NoCredentials.getInstance());
            if (logger.isDebugEnabled()) {
                logger.debug("Using custom GCS endpoint: {}", endpoint);
            }
        } else {
            // Production: use credentials file or default credentials

    }

    // Helper method to manually calculate HMACT64 for verification
    private byte[] calculateHMACT64Manually(byte[] key, byte[] data) throws NoSuchAlgorithmException {
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] ipad = new byte[64];
        byte[] opad = new byte[64];

        // HMACT64 specific: truncate key to 64 bytes if needed
        int keyLen = Math.min(key.length, 64);

     * @throws NoSuchAlgorithmException if the algorithm is not available
     */
    @Test
    void testDecryptDes() throws GeneralSecurityException, NoSuchAlgorithmException {
        KeyGenerator keyGen = KeyGenerator.getInstance("DES");
        keyGen.init(56);
        SecretKey secretKey = keyGen.generateKey();
        Key key = new KerberosKey(null, secretKey.getEncoded(), KerberosConstants.DES_ENC_TYPE, 0);

  public <T extends B> @Nullable T putInstance(
      Class<@NonNull T> type, @ParametricNullness T value) {
    return cast(type, put(type, value));
  }

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(Class<T> type) {
    return cast(type, get(type));
  }

  @CanIgnoreReturnValue
  private static <T> @Nullable T cast(Class<T> type, @Nullable Object value) {
    return Primitives.wrap(type).cast(value);
  }

    private static final ScheduledJobDbm _instance = new ScheduledJobDbm();

    private ScheduledJobDbm() {
    }

    public static ScheduledJobDbm getInstance() {
        return _instance;
    }

    // ===================================================================================
    //                                                                       Current DBDef

        return "user";
    }

    @Override
    public String asEsSearchType() {
        return "user";
    }

    @Override
    public UserDbm asDBMeta() {
        return UserDbm.getInstance();
    }

    @Override
    protected <RESULT extends User> RESULT createEntity(Map<String, Object> source, Class<? extends RESULT> entityType) {
        try {
            final RESULT result = entityType.newInstance();

    private static final FileConfigDbm _instance = new FileConfigDbm();

    private FileConfigDbm() {
    }

    public static FileConfigDbm getInstance() {
        return _instance;
    }

    // ===================================================================================
    //                                                                       Current DBDef