code: def StringEscape(self, string, match, **unused_kwargs):
      
      if match.group(1) in '\\\'"rnbt\\.ws':
        self.string += codecs.decode(string, 'unicode_escape')
      else:
        raise errors.ParseError('Invalid escape character {0:s}.'.format(string))
docs: Escape backslashes found inside a string quote.
  
      Backslashes followed by anything other than [\'"rnbt.ws] will raise
      an Error.
  
      Args:
        string: The string that matched.
        match: the match object (instance of re.MatchObject).
               Where match.group(1) contains the escaped code.
  
      Raises:
        ParseError: When the escaped string is not one of [\'"rnbt]