assertNull(dataStoreParams.getAsString("nonExistentKey"));
        assertEquals("defaultValue", dataStoreParams.getAsString("nonExistentKey", "defaultValue"));

        dataStoreParams.put("nullKey", null);
        assertEquals("defaultValue", dataStoreParams.getAsString("nullKey", "defaultValue"));
    }

        assertNotNull(capturedCallback.get());
        assertNotNull(capturedParams.get());
        assertEquals("value1", capturedParams.get().getAsString("key1"));
        assertEquals("value2", capturedParams.get().getAsString("key2"));
    }

    @Test
    public void test_store_withNullConfig() {
        // Test store with null config
        final AtomicBoolean storeCalled = new AtomicBoolean(false);

     * @param key The key of the setting.
     * @param defaultValue The default value if the setting is not found.
     * @return The setting value as a String.
     */
    public String getAsString(final String key, final String defaultValue) {
        return getAs(key, defaultValue, s -> s);
    }

    /**
     * Retrieves a setting value as an int.
     * @param key The key of the setting.

         *
         * @param value The Date object to convert.
         * @return The ISO 8601 formatted date string, or null if value is not a Date.
         */
        @Override
        public String getAsString(final Object value) {
            if (value instanceof Date) {
                return DEFAULT_DATE_PRINTER.print(((Date) value).getTime());
            }
            return null;
        }

        /**

        badWords = settings.badword().get(true);
        tagFieldNames = settings.getAsString(SuggestSettings.DefaultKeys.TAG_FIELD_NAME, StringUtil.EMPTY).split(",");
        roleFieldName = settings.getAsString(SuggestSettings.DefaultKeys.ROLE_FIELD_NAME, StringUtil.EMPTY);
        langFieldName = settings.getAsString(SuggestSettings.DefaultKeys.LANG_FIELD_NAME, StringUtil.EMPTY);

         * </ul>
         */
        private void deleteOldDocs() {
            if (Constants.FALSE.equals(initParamMap.getAsString(DELETE_OLD_DOCS))) {
                return;
            }
            final String sessionId = initParamMap.getAsString(Constants.SESSION_ID);
            if (StringUtil.isBlank(sessionId)) {

            }
        }
        try {
            if (value.getClass() == String.class) {
                return converter.getAsObject((String) value);
            }
            return converter.getAsString(value);
        } catch (final Throwable cause) {
            throw new ConverterRuntimeException(destPropertyName, value, cause);
        }
    }

    /**

        this.normalizer = Objects.requireNonNull(normalizer, "normalizer must not be null");
        this.analyzer = Objects.requireNonNull(analyzer, "analyzer must not be null");
        index = settings.getAsString(SuggestSettings.DefaultKeys.INDEX, StringUtil.EMPTY);
        this.threadPool = Objects.requireNonNull(threadPool, "threadPool must not be null");

        if (logger.isDebugEnabled()) {

     * @return the parameter value as a string, or the default value if not found
     */
    protected String getParamValue(final DataStoreParams paramMap, final String key, final String defaultValue) {
        return paramMap.getAsString(key, defaultValue);
    }

    /**
     * Adds a document to the search index by crawling the specified URL and processing the content.

     * @throws IllegalAccessRuntimeException {@link IllegalAccessException} if an error occurs
     * @see #getString(Field, Object)
     */
    public static String getString(final Field field) throws IllegalAccessRuntimeException {
        assertArgumentNotNull("field", field);

        return getString(field, null);
    }

    /**
     * Returns the value of a {@link Field} as a {@link String}.
     *