final Map<String, Object> result = indexUpdater.ingest(accessResult, doc);

        assertNotNull(result);
        // Result should be the same as input doc when ingester is null or doesn't modify
        assertSame(doc, result);
    }

    // Test ingest with exception in ingester
    public void test_ingest_withException() {

    }

    /**
     * Registers this ingester with the ingest factory.
     * This makes the ingester available for processing documents.
     */
    public void register() {
        getIngestFactory().add(this);
    }

    /**
     * Gets the ingest factory instance for managing ingesters.
     *
     * @return the ingest factory instance
     */
    protected IngestFactory getIngestFactory() {

     *
     * @param ingester the ingester to add
     */
    public synchronized void add(final Ingester ingester) {
        if (logger.isDebugEnabled()) {
            logger.debug("Loaded {}", ingester.getClass().getSimpleName());
        }
        final Ingester[] newIngesters = Arrays.copyOf(ingesters, ingesters.length + 1);
        newIngesters[ingesters.length] = ingester;

        if (ingestFactory == null) {
            return resultData;
        }
        ResultData target = resultData;
        for (final Ingester ingester : ingestFactory.getIngesters()) {
            try {
                target = ingester.process(target, responseData);
            } catch (final Exception e) {

        assertEquals(2, ingesters[1].getPriority());
        assertEquals(3, ingesters[2].getPriority());
    }

    public void test_add_2() {
        IngestFactory factory = new IngestFactory();
        factory.add(new TestIngester(3));
        factory.add(new TestIngester(2));
        factory.add(new TestIngester(1));
        Ingester[] ingesters = factory.getIngesters();

    }

    private static class TestIngestFactory extends IngestFactory {
        List<Ingester> ingesters = new ArrayList<>();

        @Override
        public Ingester[] getIngesters() {
            return ingesters.toArray(new Ingester[0]);
        }
    }

    private static class TestIngester extends Ingester {
        int processCalled = 0;

        @Override

            return dataMap;
        }
        Map<String, Object> target = dataMap;
        for (final Ingester ingester : ingestFactory.getIngesters()) {
            try {
                target = ingester.process(target, paramMap);
            } catch (final Exception e) {
                logger.warn("Failed to process Ingest[{}]", ingester.getClass().getSimpleName(), e);
            }
        }
        return target;
    }

            return map;
        }
        Map<String, Object> target = map;
        for (final Ingester ingester : ingestFactory.getIngesters()) {
            try {
                target = ingester.process(target, accessResult);
            } catch (final Exception e) {
                logger.warn("Failed to process Ingest[{}]", ingester.getClass().getSimpleName(), e);
            }
        }
        return target;
    }

                    return null;
                }

                // Check for nested map
                if (params.containsKey("nested") && params.get("nested") instanceof Map) {
                    @SuppressWarnings("unchecked")
                    Map<String, Object> nestedMap = (Map<String, Object>) params.get("nested");
                    if (nestedMap.containsKey("innerKey")) {

    }

    // Test evaluate method with nested expressions
    public void test_evaluate_withNestedExpressions() {
        String template = "${level1.level2.value}";
        Map<String, Object> paramMap = new HashMap<>();
        Map<String, Object> level2 = new HashMap<>();
        level2.put("value", "nested");
        Map<String, Object> level1 = new HashMap<>();