code: func (s *StanLogger) ReopenLogFile() {
  	s.mu.Lock()
  	if s.lfile == "" {
  		s.mu.Unlock()
  		s.Noticef("File log re-open ignored, not a file logger")
  		return
  	}
  	if l, ok := s.log.(io.Closer); ok {
  		if err := l.Close(); err != nil {
  			s.mu.Unlock()
  			s.Errorf("Unable to close logger: %v", err)
  			return
  		}
  	}
  	fileLog := natsdLogger.NewFileLogger(s.lfile, s.ltime, s.debug, s.trace, true)
  	s.log = fileLog
  	s.mu.Unlock()
  	s.Noticef("File log re-opened")
  }
docs: // ReopenLogFile closes and reopen the logfile.
  // Does nothing if the logger is not a file based.