void getConfig_returnsConfig() {
        SmbTreeConnection c = newConn();
        assertSame(config, c.getConfig());
    }

    @Test
    @DisplayName("acquire calls tree.acquire on first usage, release calls tree.release at zero")
    void acquire_release_lifecycle() {
        SmbTreeConnection c = newConn();
        SmbTreeImpl tree = mock(SmbTreeImpl.class);