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

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