Tries to guess the talks theme, or returns 'Unknown' if no theme was found.
- element = soup.find('ul', 'relatedThemes').li.a
+ element = soup.find('ul', 'relatedThemes notranslate').li.a
- "Failed to guess the theme of '%s'",
+ # If one of the child nodes isn't found in the parse tree Beautiful Soup
+ # will return `None`. Trying to access any of the `None`s child nodes
+ # will raise an `AttributeError`.
+ "Failed to guess the theme of '%s'",
def _find_download_url(soup, quality_marker):