func (pc *PipeConns) Close() error {
	pc.stopChLock.Lock()
	select {
	case <-pc.stopCh:
	default:
		close(pc.stopCh)
	}
	pc.stopChLock.Unlock()

	return nil
}
func (pc *PipeConns) Close() error {
	pc.stopChLock.Lock()
	select {
	case <-pc.stopCh:
	default:
		close(pc.stopCh)
	}
	pc.stopChLock.Unlock()

	return nil
}
// Close closes pipe connections.