### Question:
StringUtils { public static boolean isEmpty(String str) { return str == null || str.length() == 0; }  static boolean isEmpty(String str); static String leftPad(String str, int size); static String leftPad(String str, int size, char padChar); static String leftPad(String str, int size, String padStr); static String padding(int repeat, char padChar);  }### Answer:
@Test public void isEmpty() { Assert.assertTrue(StringUtils.isEmpty(null)); Assert.assertTrue(StringUtils.isEmpty("")); Assert.assertFalse(StringUtils.isEmpty(" ")); Assert.assertFalse(StringUtils.isEmpty("bob")); Assert.assertFalse(StringUtils.isEmpty(" bob ")); }