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: preferredimports.go
    path of file: ./repos/kubernetes/cmd/preferredimports
    
    the code of the file until where you have to start completion: /*
Copyright 2019 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// verify that all the imports have our preferred alias(es).
package main

import (
	"bytes"
	"encoding/json"
	"flag"
	"fmt"
	"go/ast"
	"go/build"
	"go/format"
	"go/parser"
	"go/token"
	"log"
	"os"
	"path/filepath"
	"regexp"
	"sort"
	"strings"

	"golang.org/x/term"
)

var (
	importAliases = flag.String("import-aliases", "hack/.import-aliases", "json file with import aliases")
	confirm       = flag.Bool("confirm", false, "update file with the preferred aliases for imports")
	regex   
    
func (a *analyzer) collect(dir string) {
	if _, ok := a.donePaths[dir]; ok {
		return
	}
	a.donePaths[dir] = nil

	// Create the AST by parsing src.
	fs, err := parser.ParseDir(a.fset, dir, nil, parser.AllErrors|parser.ParseComments)

	if err != nil {
		fmt.Fprintln(os.Stderr, "ERROR(syntax)", logPrefix, err)
		a.failed = true
		return
	}

	for _, p := range fs {
		// returns first error, but a.handleError deals with it
		files := a.filterFiles(p.Files)
		for _, file := range files {
			replacements := make(map[string]string)
			pathToFile := a.fset.File(file.Pos()).Name()
			for _, imp := range file.Imports {
				importPath := strings.Replace(imp.Path.Value, "\"", "", -1)
				pathSegments := strings.Split(importPath, "/")
				importName := pathSegments[len(pathSegments)-1]
				if imp.Name != nil {
					importName = imp.Name.Name
				}
				for re, template := range aliases {
					match := re.FindStringSubmatchIndex(importPath)
					if match == nil {
						// No match.
						continue
					}
					if match[0] > 0 || match[1] < len(importPath) {
						// Not a full match.
						continue
					}
					alias := string(re.ExpandString(nil, template, importPath, match))
					if alias != importName {
						if !*confirm {
							fmt.Fprintf(os.Stderr, "%sERROR wrong alias for import \"%s\" should be %s in file %s\n", logPrefix, importPath, alias, pathToFile)
							a.failed = true
						}
						replacements[importName] = alias
						if imp.Name != nil {
							imp.Name.Name = alias
						} else {
							imp.Name = ast.NewIdent(alias)
						}
					}
					break
				}
			}

			if len(replacements) > 0 {
				if *confirm {
					fmt.Printf("%sReplacing imports with aliases in file %s\n", logPrefix, pathToFile)
					for key, value := range replacements {
						renameImportUsages(file, key, value)
					}
					ast.SortImports(a.fset, file)
					var buffer bytes.Buffer
					if err = format.Node(&buffer, a.fset, file); err != nil {
						panic(fmt.Sprintf("Error formatting ast node after rewriting import.\n%s\n", err.Error()))
					}

					fileInfo, err := os.Stat(pathToFile)
					if err != nil {
						panic(fmt.Sprintf("Error stat'ing file: %s\n%s\n", pathToFile, err.Error()))
					}

					err = os.WriteFile(pathToFile, buffer.Bytes(), fileInfo.Mode())
					if err != nil {
						panic(fmt.Sprintf("Error writing file: %s\n%s\n", pathToFile, err.Error()))
					}
				}
			}
		}
	}
}