How to use the pyvirtualdisplay.xvfb.XvfbDisplay function in PyVirtualDisplay

def test_is_started():
    #     d = Display()
    #     assert not d._is_started
    #     d.start()
    #     assert d._is_started
    #     d.stop()
    #     assert d._is_started

    # with Display() as d:
    #     assert d._is_started
    # assert d._is_started

    with XvfbDisplay() as d:
        assert d._is_started
    assert d._is_started

    with Display():
        with XephyrDisplay() as d:
            assert d._is_started
        assert d._is_started

def test_repr_xvfb():
    display = Display()
    print(repr(display))

    display = Display(visible=False)
    print(repr(display))

    display = Display(backend="xvfb")
    print(repr(display))

    display = XvfbDisplay()
    print(repr(display))

def test_display():
    d = Display()
    assert d.display is None
    d.start()
    assert d.display >= 0

    d = XvfbDisplay()
    assert d.display is None
    d.start()
    assert d.display >= 0

def test_pid():
    with Display() as d:
        assert d.pid > 0
    with XvfbDisplay() as d:
        assert d.pid > 0