verification()
    }

    @Canonical
    protected class VerificationErrorHelper {
        final boolean terse

        void whenTerse(String whenTerse) {
            if (terse) {
                failure.assertHasCause(whenTerse)
            }
        }

        void whenVerbose(String whenVerbose) {
            if (!terse) {
                failure.assertHasCause(whenVerbose)