AbstractSignalNotificationHandler { protected static void assertNotNull(final Object obj, final String message, final Object... arguments) { if (obj == null) { throw new NullPointerException(String.format(message, arguments)); } } protected  AbstractSignalNotificationHandler(); boolean registerListener(final SignalListener listener); boolean unregisterListener(final SignalListener listener);  }
@Test public void assertNotNullWithNonNullValueDoesNotThrow() { AbstractSignalNotificationHandler.assertNotNull(new Object(), "TEST"); }
@Test public void assertNotNullWithNullValueThrowsNullPointerException() { assertThatThrownBy(() -> AbstractSignalNotificationHandler.assertNotNull(null, "Expected %1$s message!", "test")).isInstanceOf(NullPointerException.class); }