fasthttputil/inmemory_listener.go
func (ln *InmemoryListener) Accept() (net.Conn, error) {
	c, ok := <-ln.conns
	if !ok {
		return nil, fmt.Errorf("InmemoryListener is already closed: use of closed network connection")
	}
	close(c.accepted)
	return c.conn, nil
}
func (ln *InmemoryListener) Accept() (net.Conn, error) {
	c, ok := <-ln.conns
	if !ok {
		return nil, fmt.Errorf("InmemoryListener is already closed: use of closed network connection")
	}
	close(c.accepted)
	return c.conn, nil
}
// Accept implements net.Listener's Accept.
//
// It is safe calling Accept from concurrently running goroutines.
//
// Accept returns new connection per each Dial call.