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: golist.go
    path of file: ./repos/devspace/vendor/golang.org/x/tools/go/packages
    
    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 packages

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"go/types"
	"io/ioutil"
	"log"
	"os"
	"path"
	"path/filepath"
	"reflect"
	"sort"
	"strconv"
	"strings"
	"sync"
	"unicode"

	exec "golang.org/x/sys/execabs"
	"golang.org/x/tools/go/internal/packagesdriver"
	"golang.org/x/tools/internal/gocommand"
	"golang.org/x/tools/internal/packagesinternal"
)

// debug controls verbose logging.
var debug, _ = strconv.ParseBool(os.Getenv("GOPACKAGESDEBUG"))

// A goTooOldError reports that the go command
// found by exec.LookPath is too old to use the new go list behavior.
type goTooOldError struct {
	error
}

// responseDeduper wraps a driverResponse, deduplicating its contents.
type responseDeduper struct {
	seenRoots    map[string]bool
	seenPackages map[string]*Package
	dr           *driverResponse
}

func newDeduper() *responseDeduper {
	return &responseDeduper{
		dr:           &driverResponse{},
		seenRoots:    map[string]bool{},
		seenPackages: map[string]*Package{},
	}
}
    
func (state *golistState) adhocPackage(pattern, query string) (*driverResponse, error) {
	response, err := state.createDriverResponse(query)
	if err != nil {
		return nil, err
	}
	// If we get nothing back from `go list`,
	// try to make this file into its own ad-hoc package.
	// TODO(rstambler): Should this check against the original response?
	if len(response.Packages) == 0 {
		response.Packages = append(response.Packages, &Package{
			ID:              "command-line-arguments",
			PkgPath:         query,
			GoFiles:         []string{query},
			CompiledGoFiles: []string{query},
			Imports:         make(map[string]*Package),
		})
		response.Roots = append(response.Roots, "command-line-arguments")
	}
	// Handle special cases.
	if len(response.Packages) == 1 {
		// golang/go#33482: If this is a file= query for ad-hoc packages where
		// the file only exists on an overlay, and exists outside of a module,
		// add the file to the package and remove the errors.
		if response.Packages[0].ID == "command-line-arguments" ||
			filepath.ToSlash(response.Packages[0].PkgPath) == filepath.ToSlash(query) {
			if len(response.Packages[0].GoFiles) == 0 {
				filename := filepath.Join(pattern, filepath.Base(query)) // avoid recomputing abspath
				// TODO(matloob): check if the file is outside of a root dir?
				for path := range state.cfg.Overlay {
					if path == filename {
						response.Packages[0].Errors = nil
						response.Packages[0].GoFiles = []string{path}
						response.Packages[0].CompiledGoFiles = []string{path}
					}
				}
			}
		}
	}
	return response, nil
}