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: main.go
    path of file: ./repos/mkcert
    
    the code of the file until where you have to start completion: // Copyright 2018 The mkcert Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Command mkcert is a simple zero-config tool to make development certificates.
package main

import (
	"crypto"
	"crypto/x509"
	"flag"
	"fmt"
	"log"
	"net"
	"net/mail"
	"net/url"
	"os"
	"os/exec"
	"os/user"
	"path/filepath"
	"regexp"
	"runtime"
	"runtime/debug"
	"strings"
	"sync"

	"golang.org/x/net/idna"
)

const shortUsage = `Usage of mkcert:

	$ mkcert -install
	Install the local CA in the system trust store.

	$ mkcert example.org
	Generate "example.org.pem" and "example.org-key.pem".

	$ mkcert example.com myapp.dev localhost 127.0.0.1 ::1
	Generate "example.com+4.pem" and "example.com+4-key.pem".

	$ mkcert "*.example.it"
	Generate "_wildcard.example.it.pem" and "_wild
    
func main() {
	if len(os.Args) == 1 {
		fmt.Print(shortUsage)
		return
	}
	log.SetFlags(0)
	var (
		installFlag   = flag.Bool("install", false, "")
		uninstallFlag = flag.Bool("uninstall", false, "")
		pkcs12Flag    = flag.Bool("pkcs12", false, "")
		ecdsaFlag     = flag.Bool("ecdsa", false, "")
		clientFlag    = flag.Bool("client", false, "")
		helpFlag      = flag.Bool("help", false, "")
		carootFlag    = flag.Bool("CAROOT", false, "")
		csrFlag       = flag.String("csr", "", "")
		certFileFlag  = flag.String("cert-file", "", "")
		keyFileFlag   = flag.String("key-file", "", "")
		p12FileFlag   = flag.String("p12-file", "", "")
		versionFlag   = flag.Bool("version", false, "")
	)
	flag.Usage = func() {
		fmt.Fprint(flag.CommandLine.Output(), shortUsage)
		fmt.Fprintln(flag.CommandLine.Output(), `For more options, run "mkcert -help".`)
	}
	flag.Parse()
	if *helpFlag {
		fmt.Print(shortUsage)
		fmt.Print(advancedUsage)
		return
	}
	if *versionFlag {
		if Version != "" {
			fmt.Println(Version)
			return
		}
		if buildInfo, ok := debug.ReadBuildInfo(); ok {
			fmt.Println(buildInfo.Main.Version)
			return
		}
		fmt.Println("(unknown)")
		return
	}
	if *carootFlag {
		if *installFlag || *uninstallFlag {
			log.Fatalln("ERROR: you can't set -[un]install and -CAROOT at the same time")
		}
		fmt.Println(getCAROOT())
		return
	}
	if *installFlag && *uninstallFlag {
		log.Fatalln("ERROR: you can't set -install and -uninstall at the same time")
	}
	if *csrFlag != "" && (*pkcs12Flag || *ecdsaFlag || *clientFlag) {
		log.Fatalln("ERROR: can only combine -csr with -install and -cert-file")
	}
	if *csrFlag != "" && flag.NArg() != 0 {
		log.Fatalln("ERROR: can't specify extra arguments when using -csr")
	}
	(&mkcert{
		installMode: *installFlag, uninstallMode: *uninstallFlag, csrPath: *csrFlag,
		pkcs12: *pkcs12Flag, ecdsa: *ecdsaFlag, client: *clientFlag,
		certFile: *certFileFlag, keyFile: *keyFileFlag, p12File: *p12FileFlag,
	}).Run(flag.Args())
}