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/goreporter/vendor/golang.org/x/tools/go/gcexportdata
    
    the code of the file until where you have to start completion: // Copyright 2017 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.

// +build ignore

// The gcexportdata command is a diagnostic tool that displays the
// contents of gc export data files.
package main

import (
	"flag"
	"fmt"
	"go/token"
	"go/types"
	"log"
	"os"

	"golang.org/x/tools/go/gcexportdata"
	"golang.org/x/tools/go/types/typeutil"
)

func main() {
	log.SetPrefix("gcexportdata: ")
	log.SetFlags(0)
	flag.Usage = func() {
		fmt.Fprintln(os.Stderr, "usage: gcexportdata file.a")
	}
	flag.Parse()
	if flag.NArg() != 1 {
		flag.Usage()
		os.Exit(2)
	}
	filename := flag.Args()[0]

	f, err := os.Open(filename)
	if err != nil {
		log.Fatal(err)
	}

	r, err := gcexportdata.NewReader(f)
	if err != nil {
		log.Fatalf("%s: %s", filename, err)
	}

	// Decode the package.
	imports := make(map[string]*types.Package)
	fset := toke
    
func main() {
	log.SetPrefix("gcexportdata: ")
	log.SetFlags(0)
	flag.Usage = func() {
		fmt.Fprintln(os.Stderr, "usage: gcexportdata file.a")
	}
	flag.Parse()
	if flag.NArg() != 1 {
		flag.Usage()
		os.Exit(2)
	}
	filename := flag.Args()[0]

	f, err := os.Open(filename)
	if err != nil {
		log.Fatal(err)
	}

	r, err := gcexportdata.NewReader(f)
	if err != nil {
		log.Fatalf("%s: %s", filename, err)
	}

	// Decode the package.
	imports := make(map[string]*types.Package)
	fset := token.NewFileSet()
	pkg, err := gcexportdata.Read(r, fset, imports, "dummy")
	if err != nil {
		log.Fatal("%s: %s", filename, err)
	}

	// Print all package-level declarations, including non-exported ones.
	fmt.Printf("package %s\n", pkg.Name())
	for _, imp := range pkg.Imports() {
		fmt.Printf("import %q\n", imp.Path())
	}
	qual := func(p *types.Package) string {
		if pkg == p {
			return ""
		}
		return p.Name()
	}
	scope := pkg.Scope()
	for _, name := range scope.Names() {
		obj := scope.Lookup(name)
		fmt.Printf("%s: %s\n",
			fset.Position(obj.Pos()),
			types.ObjectString(obj, qual))

		// For types, print each method.
		if _, ok := obj.(*types.TypeName); ok {
			for _, method := range typeutil.IntuitiveMethodSet(obj.Type(), nil) {
				fmt.Printf("%s: %s\n",
					fset.Position(method.Obj().Pos()),
					types.SelectionString(method, qual))
			}
		}
	}
}