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

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

    // Test getAsString with default value and non-String value

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

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

     * @return the parameter value as a String, or defaultValue if not found
     */
    public String getAsString(final String key, final String defaultValue) {
        final String value = getAsString(key);
        if (value != null) {
            return value;
        }
        return defaultValue;
    }

    /**

            defaultDataMap.put(fessConfig.getIndexFieldExpires(), documentExpires);
        }
        // segment
        defaultDataMap.put(fessConfig.getIndexFieldSegment(), initParamMap.getAsString(Constants.SESSION_ID));
        // created
        defaultDataMap.put(fessConfig.getIndexFieldCreated(), systemHelper.getCurrentTime());
        // boost

    }

    /**
     * @throws Exception
     */
    @Test
    public void testGetAsString() throws Exception {
        final NumberConverter converter = new NumberConverter("##0");
        assertThat(converter.getAsString(Integer.valueOf("100")), is("100"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIsTarget() throws Exception {

         * </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)) {
                logger.warn("Invalid sessionId at {}", dataConfig);

            }
        }
        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);
        }
    }

    /**

     * @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.

     * @see ResourceBundle#getString(String)
     */
    public static String getString(final ResourceBundle bundle, final String key) {
        assertArgumentNotNull("bundle", bundle);
        assertArgumentNotEmpty("key", key);

        try {
            return bundle.getString(key);
        } catch (final Throwable t) {
            return null;
        }
    }

            final String pattern = ResourceBundleUtil.getString(resourceBundle, key);
            if (pattern != null) {
                return pattern;
            }
        }
        return resourceBundle.getString(messageCode);
    }

    /**
     * Returns the system name.
     *
     * @param messageCode