Strings { public static boolean isNotEmpty(String s) { return s != null && !s.isEmpty(); }  static String join(Iterable<?> col, String separator); static boolean isBlank(String s); static boolean isNotBlank(String s); static boolean isEmpty(String s); static boolean isNotEmpty(String s); static List<String> splitAndTrim(String value, String regex); static String trim(String s); static String trimToNull(String s); static String joinClassNames(Iterable<?> iterable); static Boolean toBoolean(String s);  }
@Test void testIsNotEmpty() { assertFalse(Strings.isNotEmpty(null)); assertFalse(Strings.isNotEmpty("")); assertTrue(Strings.isNotEmpty(" ")); assertTrue(Strings.isNotEmpty("foo")); }