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

        assertEquals("settings-test.suggest", settings.getAsString(SuggestSettings.DefaultKeys.INDEX, ""));
        assertEquals("content", settings.array().get(SuggestSettings.DefaultKeys.SUPPORTED_FIELDS)[0]);
        assertEquals("label,virtual_host", settings.getAsString(SuggestSettings.DefaultKeys.TAG_FIELD_NAME, ""));
        assertEquals("role", settings.getAsString(SuggestSettings.DefaultKeys.ROLE_FIELD_NAME, ""));
    }

    @Test

        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

        final java.sql.Timestamp result = (java.sql.Timestamp) converter.getAsObject("2008/12/31 12:34:56");
        System.out.println(result);
        assertThat(converter.getAsString(result), is("2008/12/31 12:34:56"));
    }

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

        final java.sql.Date result = (java.sql.Date) converter.getAsObject("2008/01/16");
        System.out.println(result);
        assertThat(converter.getAsString(result), is("2008/01/16"));
    }

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

    }

    /**
     * @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 {

            return new DecimalFormat(pattern).parse(value);
        } catch (final ParseException e) {
            throw new ParseRuntimeException(e);
        }

    }

    @Override
    public String getAsString(final Object value) {
        if (value == null) {
            return null;
        }
        return new DecimalFormat(pattern).format(value);
    }

    @Override

        if (isEmpty(value)) {
            return null;
        }
        return TimestampConversionUtil.toSqlTimestamp(value, pattern);
    }

    @Override
    public String getAsString(final Object value) {
        if (value == null) {
            return null;
        }
        return StringConversionUtil.toString((Date) value, pattern);
    }

    @Override