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: sync_test.go
    path of file: ./repos/rclone/fs/sync
    
    the code of the file until where you have to start completion: // Test sync/copy/move

package sync

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"os/exec"
	"runtime"
	"sort"
	"strings"
	"testing"
	"time"

	mutex "sync" // renamed as "sync" a
    
func TestCopyRedownload(t *testing.T) {
	ctx := context.Background()
	r := fstest.NewRun(t)
	file1 := r.WriteObject(ctx, "sub dir/hello world", "hello world", t1)
	r.CheckRemoteItems(t, file1)

	ctx = predictDstFromLogger(ctx)
	err := CopyDir(ctx, r.Flocal, r.Fremote, false)
	require.NoError(t, err)
	testLoggerVsLsf(ctx, r.Fremote, operations.GetLoggerOpt(ctx).JSON, t)

	// Test with combined precision of local and remote as we copied it there and back
	r.CheckLocalListing(t, []fstest.Item{file1}, nil)
}