def METHOD_NAME(fs, remote_dir):
    if remote_dir != "/":
        remote_dir = remote_dir + "/"
    fs.mkdir(remote_dir + "dir/")
    assert fs.isdir(remote_dir + "dir/")
    assert len(fs.ls(remote_dir + "dir/")) == 0
    fs.mkdir(remote_dir + "dir/sub", create_parents=False)
    assert fs.isdir(remote_dir + "dir/sub")