assertEquals(expectedNt, actual.get(), String.format("NTSTATUS for %08x should be %08x", dosErr, expectedNt));
    }

    @Test
    @DisplayName("Unknown DOS error code yields empty Optional")
    void testUnknownCode() {
        Optional<Integer> noMatch = findNtStatus(0xdeadbeef);
        assertFalse(noMatch.isPresent(), "Mapping for unknown code should be absent");
    }

    @Test