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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def extract_links_from_lecture(self, course_id, video_id, subtitle_language='en', resolution='540p'):
 """ Return the download URLs of on-demand course video. @param video_id: Video ID. @type video_id: str @param subtitle_language: Subtitle language. @type subtitle_language: str @param resolution: Preferred video resolution. @type resolution: str @return: @see CourseraOnDemand._extract_links_from_text """

        try:
            links = self._extract_videos_and_subtitles_from_lecture(
                course_id, video_id, subtitle_language, resolution)

            assets = self._get_lecture_asset_ids(course_id, video_id)
            assets = self._normalize_assets(assets)
            extend_supplement_links(
                links, self._extract_links_from_lecture_assets(assets))

            return links
        except requests.exceptions.HTTPError as exception:
            logging.error('Could not download lecture %s: %s',
                          video_id, exception)
            if is_debug_run():
                logging.exception(
                    'Could not download lecture %s: %s', video_id, exception)
            return None