f.set(c, tree);
        } catch (Exception e) {
            throw new AssertionError(e);
        }
    }

    // Helper to set private flag 'treeAcquired'
    private static void setTreeAcquired(SmbTreeConnection c, boolean val) {
        try {
            Field f = SmbTreeConnection.class.getDeclaredField("treeAcquired");
            f.setAccessible(true);
            f.set(c, val);