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: sizes.go
    path of file: ./repos/plumber/vendor/golang.org/x/tools/go/internal/packagesdriver
    
    the code of the file until where you have to start completion: // Copyright 2018 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 packagesdriver fetches type sizes for go/packages and go/analysis.
package packagesdriver

import (
	"context"
	"fmt"
	"go/types"
	"strings"

	"golang.org/x/tools/internal/gocommand"
)

var debug = false

func GetSizesGolist(ctx context.Context, inv gocommand.Invocation, gocmdRunner *gocommand.Runner) (types.Sizes, error) {
	inv.Verb = "list"
	inv.Args = []string{"-f", "{{context.GOARCH}} {{context.Compiler}}", "--", "unsafe"}
	stdout, stderr, friendlyErr, rawErr := gocmdRunner.RunRaw(ctx, inv)
	var goarch, compiler string
	if rawErr != nil {
		if rawErrMsg := rawErr.Error(); strings.Contains(rawErrMsg, "cannot find main module") || strings.Contains(rawErrMsg, "go.mod file not
    
func GetSizesGolist(ctx context.Context, inv gocommand.Invocation, gocmdRunner *gocommand.Runner) (types.Sizes, error) {
	inv.Verb = "list"
	inv.Args = []string{"-f", "{{context.GOARCH}} {{context.Compiler}}", "--", "unsafe"}
	stdout, stderr, friendlyErr, rawErr := gocmdRunner.RunRaw(ctx, inv)
	var goarch, compiler string
	if rawErr != nil {
		if rawErrMsg := rawErr.Error(); strings.Contains(rawErrMsg, "cannot find main module") || strings.Contains(rawErrMsg, "go.mod file not found") {
			// User's running outside of a module. All bets are off. Get GOARCH and guess compiler is gc.
			// TODO(matloob): Is this a problem in practice?
			inv.Verb = "env"
			inv.Args = []string{"GOARCH"}
			envout, enverr := gocmdRunner.Run(ctx, inv)
			if enverr != nil {
				return nil, enverr
			}
			goarch = strings.TrimSpace(envout.String())
			compiler = "gc"
		} else {
			return nil, friendlyErr
		}
	} else {
		fields := strings.Fields(stdout.String())
		if len(fields) < 2 {
			return nil, fmt.Errorf("could not parse GOARCH and Go compiler in format \"<GOARCH> <compiler>\":\nstdout: <<%s>>\nstderr: <<%s>>",
				stdout.String(), stderr.String())
		}
		goarch = fields[0]
		compiler = fields[1]
	}
	return types.SizesFor(compiler, goarch), nil
}