@ParameterizedTest
    @NullSource
    @ValueSource(strings = { "", "error", "detailed message" })
    @DisplayName("Message+Cause ctor: propagates message/cause and unsuccessful status")
    void messageAndCauseConstructor_setsMessageCause_andUnsuccessfulStatus(String msg) {
        // Arrange
        Throwable cause = new IllegalStateException("root cause");

        // Act