}

    public void test_convertFyu_BugFix() {
        // Test that フュ correctly maps to "fyu" only (not "hyu")
        List<String> results = converter.convert("フュ", null);
        assertTrue(results.contains("fyu"));
        assertFalse("Should not contain 'hyu' (that's for ヒュ)", results.contains("hyu"));
    }

    public void test_convertEmptyString() {
        List<String> results = converter.convert("", null);

        map.put("ニュ", new String[] { "nyu" });
        map.put("ニョ", new String[] { "nyo" });

        map.put("ヒャ", new String[] { "hya" });
        map.put("ヒュ", new String[] { "hyu" });
        map.put("ヒョ", new String[] { "hyo" });

        map.put("フャ", new String[] { "fya" });
        map.put("フュ", new String[] { "fyu" });
        map.put("フョ", new String[] { "fyo" });