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: flags.go
    path of file: ./repos/arvados/lib/cli
    
    the code of the file until where you have to start completion: // Copyright (C) The Arvados Authors. All rights reserved.
//
// SPDX-License-Identifier: Apache-2.0

package cli

import (
	"flag"

	"git.arvados.org/arvados.git/lib/cmd"
	"rsc.io/getopt"
)

type LegacyFlagValues struct {
	Format  string
	DryRun  bool
	Short   b
    
func LegacyFlagSet() (cmd.FlagSet, *LegacyFlagValues) {
	values := &LegacyFlagValues{Format: "json"}
	flags := getopt.NewFlagSet("", flag.ContinueOnError)
	flags.BoolVar(&values.DryRun, "dry-run", false, "Don't actually do anything")
	flags.Alias("n", "dry-run")
	flags.StringVar(&values.Format, "format", values.Format, "Output format: json, yaml, or uuid")
	flags.Alias("f", "format")
	flags.BoolVar(&values.Short, "short", false, "Return only UUIDs (equivalent to --format=uuid)")
	flags.Alias("s", "short")
	flags.BoolVar(&values.Verbose, "verbose", false, "Print more debug/progress messages on stderr")
	flags.Alias("v", "verbose")
	return flags, values
}