def METHOD_NAME(self) -> None:
    """Initiate downloads of each url in `self._urls`."""
    if self._started:
        raise ValueError("This download has already been initiated")
    self._started = True
    if not self._urls:
        self._finished = True
        self.all_downloads_finished.emit(self._done_count)
        return
    for url in self._urls:
        self._download_blocklist_url(url)
    self._finished_registering_downloads = True
    if not self._in_progress and not self._finished:
        # The in-progress list is empty but we still haven't called the
        # completion callback yet. This happens when all downloads finish
        # before we've set `_finished_registering_dowloads` to False.
        self._finished = True
        self.all_downloads_finished.emit(self._done_count)