byte[] encrypted = storage.encryptCredentials(null);
        assertNull(encrypted, "Encrypting null should return null");

        char[] decrypted = storage.decryptCredentials(null);
        assertNull(decrypted, "Decrypting null should return null");
    }

    @Test
    public void testEncryptDecryptLongPassword() throws Exception {
        // Test with very long password

     * @return the embedded file, or null if not found
     */
    protected PDEmbeddedFile getEmbeddedFile(final PDComplexFileSpecification fileSpec) {
        // search for the first available alternative of the embedded file
        PDEmbeddedFile embeddedFile = null;
        if (fileSpec != null) {
            embeddedFile = fileSpec.getEmbeddedFileUnicode();
            if (embeddedFile == null) {

     * @param schema
     *            Schema file. Must not be {@literal null}.
     * @return {@link Schema}
     */
    public static Schema newSchema(final SchemaFactory factory, final File schema) {
        assertArgumentNotNull("factory", factory);
        assertArgumentNotNull("schema", schema);

        try {
            return factory.newSchema(schema);

            final byte[] unicodeHash) {
        if (domain == null || username == null || ansiHash == null || unicodeHash == null) {
            throw new IllegalArgumentException("External credentials cannot be null");
        }
        this.domain = domain;
        this.username = username;
        this.password = null;
        this.challenge = challenge;
        this.ansiHash = ansiHash;

    }

    /**
     * Asserts that the argument is not <code>null</code>.
     *
     * @param argName
     *            The name of the argument that must not be {@code null}.
     * @param argValue
     *            The value of the argument.
     * @throws NullArgumentException
     *             If the argument is <code>null</code>.
     */

        assertNull(exception.getCause());
        assertNull(exception.getMessage());
        assertTrue(exception instanceof FessSystemException);
    }

    public void test_constructorWithNullMessageAndCause() {
        // Test constructor with null message and null cause
        SearchQueryException exception = new SearchQueryException(null, null);

        assertNull(exception.getMessage());

        RoleCQ cq = new RoleCQ();
        if (queryLambda != null) {
            queryLambda.callback(cq);
        }
        FilterAggregationBuilder builder = regFilterA(name, cq.getQuery());
        if (opLambda != null) {
            opLambda.callback(builder);
        }
        if (aggsLambda != null) {
            RoleCA ca = new RoleCA();
            aggsLambda.callback(ca);

        if (upperBound != null) {
          map = map.headMap(upperBound);
        }
        return map;
      }
      return null;
    }

    @Override
    void maintainEmptyInvariant() {
      updateWholeRowField();
      if (wholeRow != null && wholeRow.isEmpty()) {
        backingMap.remove(rowKey);
        wholeRow = null;
        backingRowMap = null;
      }
    }

    @Override

    public void test_add_nullEngine() {
        try {
            scriptEngineFactory.add("test", null);
            fail("Should throw IllegalArgumentException for null engine");
        } catch (IllegalArgumentException e) {
            assertEquals("name or scriptEngine is null.", e.getMessage());
        }
    }

    // Test add method with both null parameters
    public void test_add_bothNull() {

        if (tf.getConfig().isDfsDisabled() || tf.getCredentials().getUserDomain() == null
                || tf.getCredentials().getUserDomain().isEmpty()) {
            return null;
        }

        if (this._domains != null && System.currentTimeMillis() > this._domains.expiration) {
            this._domains = null;
        }
        if (this._domains != null) {
            return this._domains.map;
        }
        try {