assertEquals("S-1-5-21-99", s);
            assertEquals(99, sid.getRid());
        }

        @Test
        @DisplayName("Textual constructor invalid format throws SmbException")
        void testTextualConstructorInvalid() {
            // Arrange
            String bad = "S-1"; // fewer than 3 tokens

            // Act + Assert
            SmbException ex = assertThrows(SmbException.class, () -> new SID(bad));