### Question:
StringUtil { public static boolean isEmpty(String str) { return str == null || str.length() == 0; }  static boolean equalsIgnoreCase(final CharSequence str1, final CharSequence str2); static boolean equals(String str1, String str2); static boolean isBlank(String str); static boolean isNotBlank(String str); static boolean isEmpty(String str); static boolean isNotEmpty(String str); static String trimToEmpty(String str); static String trim(String str); static String capitalize(String str); static final String EMPTY; }### Answer:
@Test public void testIsEmpty() { Assert.assertFalse(StringUtil.isEmpty("bar")); Assert.assertTrue(StringUtil.isEmpty("")); }