How to use the qtile.libqtile.config function in 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')

class Config:

    auto_fullscreen = True
    main = None
    groups = [
        config.Group('g0'),
        config.Group('g1'),
        config.Group('g2'),
        config.Group('g3')
    ]
    layouts = [Plasma()]
    floating_layout = Floating()
    keys = []
    mouse = []
    screens = []
    follow_mouse_focus = False

def plasma_config(func):
    config = mark.parametrize('qtile', [Config], indirect=True)(func)
    return no_xinerama(config)

def tree(qtile):
    return qtile.c.layout.info()['tree']

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')

class Config:

    auto_fullscreen = True
    main = None
    groups = [
        config.Group('g0'),
        config.Group('g1'),
        config.Group('g2'),
        config.Group('g3')
    ]
    layouts = [Plasma()]
    floating_layout = Floating()
    keys = []
    mouse = []
    screens = []
    follow_mouse_focus = False

def plasma_config(func):
    config = mark.parametrize('qtile', [Config], indirect=True)(func)
    return no_xinerama(config)

def tree(qtile):