static String describe(Throwable t) {
    if (t == null) {
      return null;
    }

    String typeDescription = t.getClass().getSimpleName();
    String message = t.getMessage();
    return typeDescription + (message != null ? ": '" + message + "'" : "");
  }
@Test
  void describingNullIsNull() {
    assertThat(ExceptionUtils.describe(null), is(nullValue()));
  }