@Test
public void testNormalizeDesc() throws Exception {

    assertEquals("aoeᶚ能", KeywordSort.normalizeDesc("{(aöÈᶚ能͓}"));
    assertEquals("", KeywordSort.normalizeDesc(null));
    assertEquals("", KeywordSort.normalizeDesc(""));
    assertEquals("", KeywordSort.normalizeDesc("            ")); // test whitespaces: 4 spaces and 1 tab
    assertEquals("", KeywordSort.normalizeDesc("'"));
    assertEquals("1", KeywordSort.normalizeDesc(".[{#$£)(//&1@"));
    assertEquals("o", KeywordSort.normalizeDesc("\u00F6"));
}