def METHOD_NAME(manager):
    client = ipc.Client(manager.sockfile)
    command = IPCCommandInterface(client)
    sh = QSh(command)
    assert sh.do_ls(None) == "bar/     group/   layout/  screen/  widget/  window/  core/  "
    assert sh.do_ls("") == "bar/     group/   layout/  screen/  widget/  window/  core/  "
    assert sh.do_ls("layout") == "layout/group/   layout/window/  layout/screen/  layout[0]/    "
    assert sh.do_cd("layout") == "layout"
    assert sh.do_ls(None) == "group/   window/  screen/"
    assert (
        sh.do_ls("screen")
        == "screen/layout/  screen/window/  screen/bar/     screen/widget/  screen/group/ "
    )