def METHOD_NAME(self, subtitle):
    # download
    url = f'https://{self.server_url}/api/files/sub/{subtitle.subtitle_id}'
    r = self.session.get(url, headers={'Referer': subtitle.page_link}, timeout=10)
    r.raise_for_status()
    # open the zip
    with zipfile.ZipFile(io.BytesIO(r.content)) as zf:
        # remove some filenames from the namelist
        namelist = [n for n in zf.namelist() if os.path.splitext(n)[1] in ['.srt', '.sub']]
        if len(namelist) > 1:
            raise ProviderError('More than one file to unzip')
        subtitle.content = fix_line_ending(zf.read(namelist[0]))