code: def log(self, txt: str) -> bool:
          
          self.nerrors += 1
          if self._logfile is not None:
              print(txt, file=self._logfile)
          return not self.logging
docs: Log txt (if any) to the log file (if any). Return value indicates whether it is ok to terminate on the first
          error or whether we need to continue processing.
  
          :param txt: text to log.
          :return: True if we aren't logging, False if we are.