"type" : "custom",
        "tokenizer" : "keyword",
        "char_filter" : ["mapping_char"],
        "filter" : ["lowercase"]
      },
      "contents_analyzer" : {
        "type" : "custom",
        "tokenizer" : "kuromoji_neologd_normal",
        "char_filter" : ["mapping_char"],
        "filter" : ["lowercase", "stopword_en_filter", "pos_filter", "content_length_filter", "limit_token_count_filter"]
      },

        }
        encodingMap.put(toLowerCase(source), target);
    }

    /**
     * Converts the given encoding string to lowercase.
     * @param enc The encoding string.
     * @return The lowercase encoding string.
     */
    protected String toLowerCase(final String enc) {
        return enc.toLowerCase(Locale.ROOT);
    }

     */
    private CharUtil() {
    }

    /**
     * Checks if the given character is a valid URL character.
     *
     * Valid URL characters include:
     * - Lowercase letters (a-z)
     * - Uppercase letters (A-Z)
     * - Digits (0-9)
     * - Special characters: . - * _ : / + % = & ? # [ ] @ ~ ! $ ' ( ) , ;
     *
     * @param c the character to check

        assertNotNull(testBuilder.initialSettings);
        assertTrue(testBuilder.initialSettings.isEmpty());
    }

    @Test
    public void testSetSettingsIndexName() {
        // Test setting index name with lowercase conversion
        SuggestSettingsBuilder result = builder.setSettingsIndexName("TEST_INDEX");
        assertEquals(builder, result); // Test method chaining
        assertEquals("test_index", builder.settingsIndexName);

 * possible readings.
 * </p>
 *
 * <p>
 * The class also utilizes ICU4J's {@link com.ibm.icu.text.Transliterator} to convert full-width characters
 * to half-width and to convert any characters to lowercase, ensuring consistency in the output.
 * </p>
 *
 * <p>
 * Example:
 * For the input "キャ", the converter might return a list containing "kya".

            // Expected
            assertTrue(e.getMessage().contains("INVALID"));
        }

        try {
            CrawlerStatus.valueOf("initializing"); // lowercase
            fail("Should throw IllegalArgumentException for lowercase value");
        } catch (IllegalArgumentException e) {
            // Expected
            assertTrue(e.getMessage().contains("initializing"));
        }

        try {

                        final List<String> list = new ArrayList<>();
                        for (final String name : metadata.names()) {
                            final String lowerName = name.toLowerCase(Locale.ROOT);
                            if (lowerName.contains("comment") || lowerName.contains("text")) {
                                final String[] values = metadata.getValues(name);
                                if (values != null) {