// Test convert with null text - this might throw exception
        String text = null;
        String field = "content";

        try {
            List<String> results = converter.convert(text, field, "en");
            assertNotNull(results);
        } catch (Exception e) {
            // Expected behavior - null text might cause exception
            assertNotNull(e);
        }
    }

 * 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".
 * For the input "ジュ", the converter might return a list containing "zyu", "ju", and "jyu".
 * </p>
 *
 */
public class KatakanaToAlphabetConverter implements ReadingConverter {
    private final Map<String, String[]> convertMap;

        assertNotNull(suggestItem);
        assertEquals(word, suggestItem.getText());
        assertEquals(boost, suggestItem.getUserBoost(), 0.001f);
        // The queryFreq and docFreq might be handled differently by SuggestItem
        assertTrue(suggestItem.getQueryFreq() >= 0);
        assertTrue(suggestItem.getDocFreq() >= 0);

        // Check readings