### Question:
GuidGenerator { public static String generateClientId() { return RandomStringUtils.random(20, true, true); } private  GuidGenerator(); static String generate(); static String generateClientId(); static String generateClientSecret();  }### Answer:
@Test public void testGenerateClientId() throws Exception { final String clientId = GuidGenerator.generateClientId(); assertNotNull(clientId); assertTrue(clientId.length() == 20); System.out.println(clientId); }