code: def _ExtractGMailSearchQuery(self, url):
      
      if 'search/' not in url:
        return None
  
      _, _, line = url.partition('search/')
      line, _, _ = line.partition('/')
      line, _, _ = line.partition('?')
  
      return line.replace('+', ' ')
docs: Extracts a search query from a GMail search URL.
  
      GMail: https://mail.google.com/mail/u/0/#search/query[/?]
  
      Args:
        url (str): URL.
  
      Returns:
        str: search query or None if no query was found.