code: func (a *AgentServer) Close() error {
  	var errors []error
  	if a.listener != nil {
  		log.Debugf("AgentServer(%v) is closing", a.listener.Addr())
  		if err := a.listener.Close(); err != nil {
  			errors = append(errors, trace.ConvertSystemError(err))
  		}
  	}
  	if a.path != "" {
  		if err := os.Remove(a.path); err != nil {
  			errors = append(errors, trace.ConvertSystemError(err))
  		}
  	}
  	return trace.NewAggregate(errors...)
  }
docs: // Close closes listener and stops serving agent