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/protobuf-go/internal/cmd/generate-corpus
    
    the code of the file until where you have to start completion: // Copyright 2019 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.

// Program generate-corpus generates a seed corpus for the fuzzers.
//
// This command is not run automatically because its output is not stable.
// It's present in source control mainly as documentation of where the seed
// corpus came from.
package main

import (
	"crypto/sha1"
	"fmt"
	"io/ioutil"
	"log"

	"google
    
func main() {
	for _, m := range messages {
		wire, err := proto.Marshal(m)
		if err != nil {
			log.Fatal(err)
		}
		if err := ioutil.WriteFile(fmt.Sprintf("internal/fuzz/wirefuzz/corpus/%x", sha1.Sum(wire)), wire, 0777); err != nil {
			log.Fatal(err)
		}

		text, err := prototext.Marshal(m)
		if err != nil {
			log.Fatal(err)
		}
		if err := ioutil.WriteFile(fmt.Sprintf("internal/fuzz/textfuzz/corpus/%x", sha1.Sum(text)), text, 0777); err != nil {
			log.Fatal(err)
		}

		json, err := protojson.Marshal(m)
		if err != nil {
			log.Fatal(err)
		}
		if err := ioutil.WriteFile(fmt.Sprintf("internal/fuzz/jsonfuzz/corpus/%x", sha1.Sum(json)), json, 0777); err != nil {
			log.Fatal(err)
		}
	}
}