<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _trigger_offline_retrieval(self, url):
 """ Triggers retrieval of an offline product Trying to download an offline product triggers its retrieval from the long term archive. The returned HTTP status code conveys whether this was successful. Parameters url : string URL for downloading the product Notes ----- https://scihub.copernicus.eu/userguide/LongTermArchive """

        with self.session.get(url, auth=self.session.auth, timeout=self.timeout) as r:
            # check https://scihub.copernicus.eu/userguide/LongTermArchive#HTTP_Status_codes
            if r.status_code == 202:
                self.logger.info("Accepted for retrieval")
            elif r.status_code == 503:
                self.logger.error("Request not accepted")
                raise SentinelAPILTAError('Request for retrieval from LTA not accepted', r)
            elif r.status_code == 403:
                self.logger.error("Requests exceed user quota")
                raise SentinelAPILTAError('Requests for retrieval from LTA exceed user quota', r)
            elif r.status_code == 500:
                # should not happen
                self.logger.error("Trying to download an offline product")
                raise SentinelAPILTAError('Trying to download an offline product', r)
            return r.status_code