Calculates vote total as total_upvotes - total_downvotes. We are adding a method here instead of relying on django-secretballot's addition since that doesn't work for subclasses.

def vote_total(self):
        """
        Calculates vote total as total_upvotes - total_downvotes. We are adding a method here instead of relying on django-secretballot's addition since that doesn't work for subclasses.
        """
        modelbase_obj = self.modelbase_obj
        return modelbase_obj.votes.filter(vote=+1).count() - modelbase_obj.votes.filter(vote=-1).count()