public void close() {
        if (runner != null) {
            try {
                client.admin()
                        .indices()
                        .prepareFlush()
                        .setForce(true)
                        .execute()
                        .actionGet(ComponentUtil.getFessConfig().getIndexIndicesTimeout());
            } catch (final Exception e) {

                return Collections.emptyList();
            }
        };
        ComponentUtil.register(requestHeaderService, RequestHeaderService.class.getCanonicalName());

        final SetOnce<Map<String, Object>> initParamMapSet = new SetOnce<>();
        WebConfig webConfig = new WebConfig();
        webConfig.setUserAgent(Constants.CRAWLING_USER_AGENT_PREFIX + "1.0" + Constants.CRAWLING_USER_AGENT_SUFFIX);

        DefaultProblemCollector collector = new DefaultProblemCollector(null);

        collector.add(null, "PROBLEM1", -1, -1, null);

        collector.setSource("SOURCE_PROBLEM2");
        collector.add(null, "PROBLEM2", -1, -1, null);

        collector.setSource("SOURCE_PROBLEM3");
        collector.add(null, "PROBLEM3", -1, -1, null);

        assertEquals("", collector.getProblems().get(0).getSource());

    default void add(ModelProblem problem) {
        getProblemCollector().reportProblem(problem);
    }

    ModelBuilderException newModelBuilderException();

    void setSource(String location);

    void setSource(Model model);

    String getSource();

    void setRootModel(Model model);

    Model getRootModel();

     * their source, but the next messages will use the new source.
     *
     * @param source a source
     */
    void setSource(String source);

    /**
     *
     * @return the collected Problems, never {@code null}
     */
    List<Problem> getProblems();

        // When/Then
        assertThrows(IllegalArgumentException.class, () -> {
            transformHeader.setNonce(shortNonce);
        });

        assertThrows(IllegalArgumentException.class, () -> {
            transformHeader.setNonce(longNonce);
        });
    }

    @Test
    @DisplayName("Should handle null signature")
    void testNullSignature() {
        // When/Then

        assertEquals(1, collector2.getProblems().size());
    }

    @Test
    void testAddProblem() {
        ProblemCollector collector = ProblemCollectorFactory.newInstance(null);
        collector.setSource("pom.xml");
        collector.add(Problem.Severity.ERROR, "Error message", 10, 5, null);
        collector.add(Problem.Severity.WARNING, "Warning message", 15, 3, null);

        List<Problem> problems = collector.getProblems();

        this.problems = (problems != null) ? problems : new ArrayList<>();
    }

    @Override
    public List<Problem> getProblems() {
        return problems;
    }

    @Override
    public void setSource(String source) {
        this.source = source;
    }

    @Override
    public void add(Problem.Severity severity, String message, int line, int column, Exception cause) {

    }

    /**
     * Sets the nonce for encryption
     *
     * @param nonce
     *            the nonce to set (12 bytes for CCM, 16 bytes for GCM)
     */
    public void setNonce(final byte[] nonce) {
        if (nonce.length == 12) {
            // For CCM cipher, pad nonce to 16 bytes with zeros
            java.util.Arrays.fill(this.nonce, (byte) 0);

    }

    protected IndexRequestBuilder createInsertRequest(final EsAbstractEntity esEntity) {
        final IndexRequestBuilder builder = client.prepareIndex().setIndex(asEsIndex()).setSource(toSource(esEntity));
        final String id = esEntity.asDocMeta().id();
        if (id != null) {
            builder.setId(id);
        }