code: func (l *appLog) Release() {
  	l.mtx.Lock()
  	defer l.mtx.Unlock()
  	l.refs--
  	if l.refs == 0 {
  		// we're the last user, clean it up
  		l.l.Close()
  		l.m.appLogsMtx.Lock()
  		delete(l.m.appLogs, l.appID)
  		l.m.appLogsMtx.Unlock()
  	}
  }
docs: // Release releases the app log, when the last job releases an app log, it is
  // closed.