docs: def match(self, path_info: str) -> MatchResult:
          """ parse path_info and detect urlvars of url pattern """
          matched = self.regex.match(path_info)
          if matched is None:
              return None
          matchlength = len(matched.group(0))
          matchdict = matched.groupdict()
  
          try:
              matchdict = self.convert_values(matchdict)
          except ValueError:
              return None
  
          return MatchResult(matchdict,
                             matchlength)