Return a queryset of messages for the request user

def _message_queryset(self, include_read=False):
        """
        Return a queryset of messages for the request user
        """
        expire = timezone.now()


        qs = PersistentMessage.objects.\
        filter(user=self.get_user()).\
        filter(Q(expires=None) | Q(expires__gt=expire))
        if not include_read:
            qs = qs.exclude(read=True)
        return qs