human
Here's a good function header given the following:
I wrote the below code

    @_preprocess_data(label_namer='z')
    def func(*args, **kwargs):
        pass
    with pytest.warns(RuntimeWarning):
        func(None, x='a', y='b')
    def real_func(x, y):
        pass
    @_preprocess_data(label_namer='x')
    def func(*args, **kwargs):
        real_func(**kwargs)
    with pytest.raises(TypeError):
        func(None, x='a', y='b')

What's a good function header?
assistant
#Here's a good function header.

def test_label_problems_at_runtime():