def METHOD_NAME(f, request, *args, **kwargs):
    if not request.user.is_authenticated:
        raise ValueError("The @person_required decorator should be called after @login_required.")
    try:
        request.user.person
    except Person.DoesNotExist:
        return render(request, 'registration/missing_person.html')
    return  f(request, *args, **kwargs)