'remove source by stop the downloading and remove its metainfo for all its swarms'

def remove_source(self, source_key):

    if (source_key in self.boosting_sources):
        source = self.boosting_sources.pop(source_key)
        source.kill_tasks()
        self._logger.info('Removed    source    %s', source_key)
        rm_torrents = [torrent for (_, torrent) in self.torrents.items() if (torrent['source'] == source_to_string(source_key))]
        for torrent in rm_torrents:
            self.stop_download(torrent)
            self.torrents.pop(torrent['metainfo'].get_infohash(), None)
        self._logger.info('Torrents    download    stopped    and    removed')
