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: things_test.go
    path of file: ./repos/magistrala/things/cache
    
    the code of the file until where you have to start completion: // Copyright (c) Abstract Machines
// SPDX-License-Identifier: Apache-2.0

package cache_test

import (
	"context"
	"fmt"
	"strings"
	"testing"
	"time"

	"github.com/absmach/magistrala/pkg/errors"
	repoerr "github.com/absmach/magistrala/pkg/errors/repository"
	"github.com/absmach/magistrala/things/cache"
	"github.com/stretchr/testify/assert"
)

const (
	testKey  = "testKey"
	testID   = "testID"
	testKey2 = "testKey2"
	testID2  = "testID2"
)

func TestSave(t *testing.T) {
	redisClient.FlushAll(context.Background())
	tscache := cache.NewCache(redisClient, 1*time.Minute)
	ctx := context.Background()

	cases := []struct {
		desc string
		key  string
		id   string
		err  error
	}{
		{
			desc: "Save thing to cache
    
func TestSave(t *testing.T) {
	redisClient.FlushAll(context.Background())
	tscache := cache.NewCache(redisClient, 1*time.Minute)
	ctx := context.Background()

	cases := []struct {
		desc string
		key  string
		id   string
		err  error
	}{
		{
			desc: "Save thing to cache",
			key:  testKey,
			id:   testID,
			err:  nil,
		},
		{
			desc: "Save already cached thing to cache",
			key:  testKey,
			id:   testID,
			err:  nil,
		},
		{
			desc: "Save another thing to cache",
			key:  testKey2,
			id:   testID2,
			err:  nil,
		},
		{
			desc: "Save thing with long key ",
			key:  strings.Repeat("a", 513*1024*1024),
			id:   testID,
			err:  repoerr.ErrCreateEntity,
		},
		{
			desc: "Save thing with long id ",
			key:  testKey,
			id:   strings.Repeat("a", 513*1024*1024),
			err:  repoerr.ErrCreateEntity,
		},
		{
			desc: "Save thing with empty key",
			key:  "",
			id:   testID,
			err:  repoerr.ErrCreateEntity,
		},
		{
			desc: "Save thing with empty id",
			key:  testKey,
			id:   "",
			err:  repoerr.ErrCreateEntity,
		},
		{
			desc: "Save thing with empty key and id",
			key:  "",
			id:   "",
			err:  repoerr.ErrCreateEntity,
		},
	}

	for _, tc := range cases {
		err := tscache.Save(ctx, tc.key, tc.id)
		if err == nil {
			id, _ := tscache.ID(ctx, tc.key)
			assert.Equal(t, tc.id, id, fmt.Sprintf("%s: expected %s got %s", tc.desc, tc.id, id))
		}
		assert.True(t, errors.Contains(err, tc.err), fmt.Sprintf("%s: expected %s got %s", tc.desc, tc.err, err))
	}
}