How to use the qtile.test.conftest.qtile.c.layout.mode_vertical function in qtile

def test_split_mode(self, qtile):
        qtile.test_window('a')
        qtile.test_window('b')
        qtile.c.layout.mode_horizontal_split()
        qtile.test_window('c')
        assert qtile.c.window.info()['width'] == 200 - 2
        qtile.c.layout.mode_vertical()
        qtile.test_window('d')
        assert qtile.c.window.info()['height'] == 300 - 2
        qtile.test_window('e')
        assert qtile.c.window.info()['height'] == 200 - 2
        qtile.c.layout.mode_vertical_split()
        qtile.test_window('f')
        assert qtile.c.window.info()['height'] == 100 - 2

def test_sizes(self, qtile):
        qtile.test_window('a')
        qtile.test_window('b')
        qtile.c.layout.mode_vertical()
        qtile.test_window('c')
        info = qtile.c.window.info()
        assert info['x'] == 400
        assert info['y'] == 300
        assert info['width'] == 400 - 2
        assert info['height'] == 300 - 2
        qtile.c.layout.grow_height(50)
        info = qtile.c.window.info()
        assert info['height'] == 300 - 2 + 50
        qtile.c.layout.grow_width(50)
        info = qtile.c.window.info()
        assert info['width'] == 400 - 2 + 50
        qtile.c.layout.reset_size()
        info = qtile.c.window.info()
        assert info['height'] == 300 - 2
        qtile.c.layout.height(300)

def test_split_directions(self, qtile):
        qtile.test_window('a')
        qtile.c.layout.mode_horizontal()
        qtile.test_window('b')
        qtile.c.layout.mode_vertical()
        qtile.test_window('c')
        assert tree(qtile) == ['a', ['b', 'c']]

def grid(qtile):
    qtile.test_window('a')
    qtile.test_window('b')
    qtile.c.layout.previous()
    qtile.c.layout.mode_vertical()
    qtile.test_window('c')
    qtile.c.layout.right()
    qtile.c.layout.mode_vertical()
    qtile.test_window('d')