{"", "[::1]:0", &TCPAddr{IP: ParseIP("::1"), Port: 0}, nil},         // Go 1.0 behavior

	{"tcp", ":12345", &TCPAddr{Port: 12345}, nil},

	{"http", "127.0.0.1:0", nil, UnknownNetworkError("http")},

	{"tcp", "127.0.0.1:http", &TCPAddr{IP: ParseIP("127.0.0.1"), Port: 80}, nil},
	{"tcp", "[::ffff:127.0.0.1]:http", &TCPAddr{IP: ParseIP("::ffff:127.0.0.1"), Port: 80}, nil},

	afnet, _, err := parseNetwork(ctx, network, false)
	if err != nil {
		return nil, err
	}
	switch afnet {
	case "ip", "ip4", "ip6":
	default:
		return nil, UnknownNetworkError(network)
	}

	if host == "" {
		return nil, newDNSError(errNoSuchHost, host, "")
	}
	addrs, err := r.internetAddrList(ctx, afnet, host)
	if err != nil {
		return nil, err
	}