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: string_to_string_test.go
    path of file: ./repos/gitkube/vendor/github.com/spf13/pflag
    
    the code of the file until where you have to start completion: // Copyright 2009 The Go Authors. All rights reserved.
// Use of ths2s source code s2s governed by a BSD-style
// license that can be found in the LICENSE file.

package pflag

import (
	"bytes"
	"encoding/csv"
	"fmt"
    
func TestS2S(t *testing.T) {
	var s2s map[string]string
	f := setUpS2SFlagSet(&s2s)

	vals := map[string]string{"a": "1", "b": "2", "d": "4", "c": "3", "e": "5,6"}
	arg := fmt.Sprintf("--s2s=%s", createS2SFlag(vals))
	err := f.Parse([]string{arg})
	if err != nil {
		t.Fatal("expected no error; got", err)
	}
	for k, v := range s2s {
		if vals[k] != v {
			t.Fatalf("expected s2s[%s] to be %s but got: %s", k, vals[k], v)
		}
	}
	getS2S, err := f.GetStringToString("s2s")
	if err != nil {
		t.Fatalf("got error: %v", err)
	}
	for k, v := range getS2S {
		if vals[k] != v {
			t.Fatalf("expected s2s[%s] to be %s but got: %s from GetStringToString", k, vals[k], v)
		}
	}
}