@Test public void testToString() { ErrorMessage em = new ErrorMessage(new RuntimeException("foo")); String emString = em.toString(); assertThat(emString, not(containsString("original"))); em = new ErrorMessage(new RuntimeException("foo"), new GenericMessage<>("bar")); emString = em.toString(); assertThat(emString, containsString("original")); assertThat(emString, containsString(em.getOriginalMessage().toString())); }