def test_default_arguments() -> None:
    'Test that default arguments are correctly recognised when they\n    are not ``None``. '

    @argcomb(a='b')
    def f(a: int=1, b: int=2) -> None:
        ...
    f(a=1)
    with pytest.raises(InvalidArgumentCombination):
        f(a=2, b=2)
Test that default arguments are correctly recognised when they
are not ``None``.
def test_default_arguments() -> None:
    'Test that default arguments are correctly recognised when they\n    are not ``None``. '

    @argcomb(a='b')
    def f(a: int=1, b: int=2) -> None:
        ...
    f(a=1)
    with pytest.raises(InvalidArgumentCombination):
        f(a=2, b=2)