### Question:
StringUtils { public static boolean isEmpty(String string) { if (string == null) { return true; } return string.isEmpty(); } StringUtils(); static boolean isEmpty(String string); static String clean(String string); static boolean isAlpha(Character c); static String getBeanName(String queueName); static String convertToCamelCase(String string); static String groupName(String name);  }### Answer:
@Test public void isEmpty() { assertTrue(StringUtils.isEmpty(null)); assertTrue(StringUtils.isEmpty("")); assertFalse(StringUtils.isEmpty("hello")); }