How to restrict users voting on their own model

I am using django-voting as a voting application for two of my models. Those both models have fields "author".

How can I restrict a user from voting on a model that has this particular user set as it's author without modifying django-voting app?

Django middleware is the first thing that comes to my mind, but I don't understand it's "proces_view" function. If you think middleware is the right way could you please give an example of how to do it.

Add this code anywhere in your settings.py:

from voting.managers import VoteManager

def check_user(func):
    def wrapper(self, obj, user, vote):
        if obj.user != user:
            return func(self, obj, user, vote)
        else:
            return None
            # or raise some exception
    return wrapper

VoteManager.record_vote = check_user(VoteManager.record_vote)

I didn't run this code, maybe it's incorrect, but I hope idea is clear