### Question:
StringUtils { public static boolean isNotEmpty(CharSequence cs) { return !isEmpty(cs); }  static boolean isEmpty(CharSequence cs); static boolean isNotEmpty(CharSequence cs); static boolean isBlank(CharSequence cs); static boolean isNotBlank(CharSequence cs); static String defaultString(final Object str); static String toString(Object o, String defaultVal); static String toString(Object o); static final String EMPTY; }### Answer:
@Test public void isNotEmpty() { Assert.assertFalse(StringUtils.isNotEmpty(null)); Assert.assertFalse(StringUtils.isNotEmpty("")); Assert.assertTrue(StringUtils.isNotEmpty(" ")); }