How to use the safety.utils.resolve function in safety

def create_session(self, request, user):
        ip = utils.resolve(app_settings.IP_RESOLVER, request)
        device = utils.resolve(app_settings.DEVICE_RESOLVER, request)
        location = utils.resolve(app_settings.LOCATION_RESOLVER, request)

        user_agent = request.META.get('HTTP_USER_AGENT', '')
        user_agent = user_agent[:200] if user_agent else user_agent

        try:
            with transaction.atomic():
                obj = self.create(
                    user=user,
                    session_key=request.session.session_key,
                    ip=ip,
                    user_agent=user_agent,
                    device=device,
                    location=location,
                    expiration_date=request.session.get_expiry_date(),
                    last_activity=now())
        except IntegrityError: