func (l *networkListener) Accept() (net.Conn, error) {
	c, err := l.Listener.Accept()
	if err != nil {
		return nil, err
	}
	l.mu.RLock()
	defer l.mu.RUnlock()
	config := l.config
	return tls.Server(c, config), nil
}
func (l *networkListener) Accept() (net.Conn, error) {
	c, err := l.Listener.Accept()
	if err != nil {
		return nil, err
	}
	l.mu.RLock()
	defer l.mu.RUnlock()
	config := l.config
	return tls.Server(c, config), nil
}
// Accept waits for and returns the next incoming TLS connection then use the
// current TLS configuration to handle it.