assertTrue(ctx.isSupported(oid));
        assertTrue(ctx.isPreferredMech(oid));
    }

    @Test
    @DisplayName("isSupported returns false for null/unknown OIDs")
    void isSupported_unknownOrNull() {
        assertFalse(ctx.isSupported(null));
        assertFalse(ctx.isPreferredMech(null));
        assertFalse(ctx.isSupported(new ASN1ObjectIdentifier("1.3.6.1.4.1.99999")));
    }

    @Test