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

    def decorator(fn):
        @wraps(fn, assigned=available_attrs(fn))
        def wrapper(self, *args, **kwargs):
            force_fresh = kwargs.pop('force_fresh', False)
            field_val = getattr(self, field_name)
            if ((field_val is not None) and (not force_fresh)):
                return field_val
            field_val = fn(self, force_fresh=force_fresh)
            setattr(self, field_name, field_val)
            return field_val
        return wrapper
    return decorator

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

def cache_with_field(field_name):