code: public static Matcher<Throwable> exceptionWithMessage(Class<? extends Throwable> type, String expectedMessage) {
          return new ExpectedException(type, expectedMessage);
      }
docs: Creates a matcher for a {@link Throwable} that matches when the provided {@code Throwable} instance is the same or a subtype
  of the given class and has the same message in the error message or the message is contained in the error message