assertNull(ctx.searchSessionKey(new javax.security.auth.Subject()));
    }

    @Test
    @DisplayName("toString shows basic info when not established")
    void toString_notEstablished() throws Exception {
        when(gssContext.isEstablished()).thenReturn(false);
        String s = ctx.toString();
        assertTrue(s.startsWith("KERB5["));
        assertTrue(s.contains("src=null"));
    }