def test_without_color():
style = Style(bold=True, color="red", bgcolor="blue")
colorless_style = style.without_color
assert colorless_style.color == None
assert colorless_style.bgcolor == None
assert colorless_style.bold == True
null_style = Style.null()
assert null_style.without_color == null_style
def test_empty():
assert Style.null() == Style()