KeyRefresherException extends Exception { public KeyRefresherException() { super(); } KeyRefresherException();  KeyRefresherException(String message, Throwable cause);  KeyRefresherException(String message);  KeyRefresherException(Throwable cause);   }
@Test public void testKeyRefresherException() { KeyRefresherException keyRefresherException = new KeyRefresherException(); assertEquals(null, keyRefresherException.getMessage()); keyRefresherException = new KeyRefresherException("exception"); assertEquals("exception", keyRefresherException.getMessage()); keyRefresherException = new KeyRefresherException(new Throwable("new throwable")); assertEquals("java.lang.Throwable: new throwable", keyRefresherException.getMessage()); keyRefresherException = new KeyRefresherException("exception", new Throwable("new throwable")); assertEquals("exception", keyRefresherException.getMessage()); }