docs: def check(self, paths):
          """
          Return list of error dicts for all found errors in paths.
  
          The default implementation expects `tool`, and `tool_err_re` to be
          defined.
  
          tool: external binary to use for checking.
          tool_err_re: regexp that can match output of `tool` -- must provide
              a groupdict with at least "filename", "lineno", "colno",
              and "msg" keys. See example checkers.
          """
          if not paths:
              return ()
  
          cmd_pieces = [self.tool]
          cmd_pieces.extend(self.tool_args)
          return self._check_std(paths, cmd_pieces)