code: def matches(self, txt: str) -> bool:
          
          # rval = ref.getText()[1:-1].encode('utf-8').decode('unicode-escape')
          if r'\\u' in self.pattern_re.pattern:
              txt = txt.encode('utf-8').decode('unicode-escape')
          match = self.pattern_re.match(txt)
          return match is not None and match.end() == len(txt)
docs: Determine whether txt matches pattern
  
          :param txt: text to check
          :return: True if match