You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: multicastlistener_test.go
    path of file: ./repos/go-in-5-minutes/episode7/vendor/golang.org/x/net/ipv4
    
    the code of the file until where you have to start completion: // Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package ipv4_test

import (
	"net"
	"runtime"
	"testing"

	"golang.org/x/net/internal/nettest"
	"golang.org/x/net/ipv4"
)

var udpMultipleGroupListenerTests = []net.Addr{
	&net.UDPAddr{IP: net.IPv4(2
    
func TestUDPPerInterfaceSinglePacketConnWithSingleGroupListener(t *testing.T) {
	switch runtime.GOOS {
	case "nacl", "plan9", "windows":
		t.Skipf("not supported on %s", runtime.GOOS)
	}
	if testing.Short() {
		t.Skip("to avoid external network")
	}

	gaddr := net.IPAddr{IP: net.IPv4(224, 0, 0, 254)} // see RFC 4727
	type ml struct {
		c   *ipv4.PacketConn
		ifi *net.Interface
	}
	var mlt []*ml

	ift, err := net.Interfaces()
	if err != nil {
		t.Fatal(err)
	}
	for i, ifi := range ift {
		ip, ok := nettest.IsMulticastCapable("ip4", &ifi)
		if !ok {
			continue
		}
		c, err := net.ListenPacket("udp4", ip.String()+":"+"1024") // unicast address with non-reusable port
		if err != nil {
			t.Fatal(err)
		}
		defer c.Close()
		p := ipv4.NewPacketConn(c)
		if err := p.JoinGroup(&ifi, &gaddr); err != nil {
			t.Fatal(err)
		}
		mlt = append(mlt, &ml{p, &ift[i]})
	}
	for _, m := range mlt {
		if err := m.c.LeaveGroup(m.ifi, &gaddr); err != nil {
			t.Fatal(err)
		}
	}
}