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: openvpnconf_test.go
    path of file: ./repos/gluetun/internal/provider/custom
    
    the code of the file until where you have to start completion: package custom

import (
	"net/netip"
	"testing"

	"github.com/qdm12/gluetun/internal/configuration/settings"
	"github.com/qdm12/gluetun/internal/constants"
	"github.com/qdm12/gluetun/internal/constants/providers"
	"github.com
    
func Test_modifyConfig(t *testing.T) {
	t.Parallel()

	testCases := map[string]struct {
		lines         []string
		settings      settings.OpenVPN
		connection    models.Connection
		ipv6Supported bool
		modified      []string
	}{
		"mixed": {
			lines: []string{
				"up bla",
				"proto tcp",
				"remote 5.5.5.5",
				"cipher bla",
				"",
				"tun-ipv6",
				"keep me here",
				"auth bla",
			},
			settings: settings.OpenVPN{
				User:        stringPtr("user"),
				Ciphers:     []string{"cipher"},
				Auth:        stringPtr("sha512"),
				MSSFix:      uint16Ptr(1000),
				ProcessUser: "procuser",
				Interface:   "tun3",
				Verbosity:   intPtr(0),
			}.WithDefaults(providers.Custom),
			connection: models.Connection{
				IP:       netip.AddrFrom4([4]byte{1, 2, 3, 4}),
				Port:     1194,
				Protocol: constants.UDP,
			},
			ipv6Supported: false,
			modified: []string{
				"up bla",
				"keep me here",
				"proto udp",
				"remote 1.2.3.4 1194",
				"dev tun3",
				"mute-replay-warnings",
				"auth-nocache",
				"pull-filter ignore \"auth-token\"",
				"auth-retry nointeract",
				"suppress-timestamps",
				"auth-user-pass /etc/openvpn/auth.conf",
				"verb 0",
				"data-ciphers-fallback cipher",
				"data-ciphers cipher",
				"auth sha512",
				"mssfix 1000",
				"pull-filter ignore \"route-ipv6\"",
				"pull-filter ignore \"ifconfig-ipv6\"",
				"user procuser",
				"persist-tun",
				"persist-key",
				"",
			},
		},
	}

	for name, testCase := range testCases {
		testCase := testCase
		t.Run(name, func(t *testing.T) {
			t.Parallel()

			modified := modifyConfig(testCase.lines,
				testCase.connection, testCase.settings, testCase.ipv6Supported)

			assert.Equal(t, testCase.modified, modified)
		})
	}
}