How to use the memorious.core.get_rate_limit function in memorious

def boot(self):
        self.scheduler = get_rate_limit('scheduler',
                                        unit=60,
                                        interval=settings.SCHEDULER_INTERVAL,
                                        limit=1)

def _rate_limit(self, url):
        resource = urlparse(url).netloc or url
        limit = self.context.get('http_rate_limit', settings.HTTP_RATE_LIMIT)
        rate_limit = get_rate_limit(resource, limit=limit)
        rate_limit.comply()

def _upsert(context, params, data):
    """Insert or update data and add/update appropriate timestamps"""
    table = params.get("table")
    table = datastore.get_table(table, primary_id=False)
    unique_keys = ensure_list(params.get("unique"))
    data["__last_seen"] = datetime.datetime.utcnow()
    if len(unique_keys):
        updated = table.update(data, unique_keys, return_count=True)
        if updated:
            return
    data["__first_seen"] = data["__last_seen"]
    rate_limit = get_rate_limit("db", limit=settings.DB_RATE_LIMIT)
    rate_limit.comply()
    table.insert(data)