verify(tree, atLeastOnce()).close();
    }

    @Test
    @DisplayName("isSame returns true only for same underlying tree instance")
    void isSame_comparesUnderlyingTreeIdentity() {
        SmbTreeConnection c1 = newConn();
        SmbTreeConnection c2 = newConn();
        SmbTreeImpl shared = mock(SmbTreeImpl.class);
        when(shared.acquire(false)).thenReturn(shared);