code: def rfc2822_datetime(s):
      
      date_tuple = parsedate(s)
      if date_tuple is None:
          return None
      return datetime.datetime(*date_tuple[:6]).replace(tzinfo=pytz.utc)
docs: Parses an RFC 2822 date string and returns a UTC datetime object,
      or the string if parsing failed.
      :param s: RFC 2822-formatted string date
      :return: datetime or str