How to use the tartube.downloads.DownloadWorker function in tartube

#   operation, any media.Video object in this list is destroyed
        self.doomed_video_list = []


        # Code
        # ----

        # Create an object for converting download options stored in
        #   downloads.DownloadWorker.options_list into a list of youtube-dl
        #   command line options
        self.options_parser_obj = options.OptionsParser(self.app_obj)

        # Create a list of downloads.DownloadWorker objects, each one handling
        #   one of several simultaneous downloads
        for i in range(1, self.app_obj.num_worker_default + 1):
            self.worker_list.append(DownloadWorker(self))

        # Let's get this party started!
        self.start()

def __init__(self, download_manager_obj):

        if DEBUG_FUNC_FLAG:
            utils.debug_time('dld 730 __init__')

        super(DownloadWorker, self).__init__()

        # IV list - class objects
        # -----------------------
        # The parent downloads.DownloadManager object
        self.download_manager_obj = download_manager_obj
        # The downloads.DownloadItem object for the current job
        self.download_item_obj = None
        # The downloads.VideoDownloader object for the current job
        self.video_downloader_obj = None
        # The options.OptionsManager object for the current job
        self.options_manager_obj = None


        # IV list - other
        # ---------------
        # A number identifying this worker, matching the number of the page

if number > current:

                # The number has increased. If any workers have marked as
                #   doomed, they can be unmarked, allowing them to continue
                match_flag = False

                for worker_obj in self.worker_list:
                    if worker_obj.doomed_flag:
                        worker_obj.set_doomed_flag(True)
                        match_flag = True
                        break

                if not match_flag:
                    # No workers were marked doomed, so create a brand new
                    #   download worker
                    self.worker_list.append(DownloadWorker(self))

            else:

                # The number has decreased. The first worker in the list is
                #   marked as doomed - that is, when it has finished its
                #   current job, it closes (rather than being given another
                #   job, as usual)
                for worker_obj in self.worker_list:
                    if not worker_obj.doomed_flag:
                        worker_obj.set_doomed_flag(True)
                        break