code: def parse_bewit(bewit):
      
      decoded_bewit = b64decode(bewit).decode('ascii')
      bewit_parts = decoded_bewit.split("\\")
      if len(bewit_parts) != 4:
          raise InvalidBewit('Expected 4 parts to bewit: %s' % decoded_bewit)
      return bewittuple(*bewit_parts)
docs: Returns a `bewittuple` representing the parts of an encoded bewit string.
      This has the following named attributes:
          (id, expiration, mac, ext)
  
      :param bewit:
          A base64 encoded bewit string
      :type bewit: str