CharactersValidator { public boolean validate(String input) { String whaaat = input.toLowerCase(); return input.equals(whaaat); }  boolean validate(String input);  }
@Test public void testLowerCaseCharactersAreValid() throws Exception { String input = "fajklsdfhkladsfj"; boolean result = validator.validate(input); assertTrue(result); }
@Test public void testUpperCaseCharactersAreNotValid() throws Exception { String input = "aaaWERWERWwerw \t"; boolean result = validator.validate(input); assertFalse(result); }