为 Shutil 添加多线程？

import osimport shutilos.mkdir('test')os.mkdir('test/source')def bench_mark(func, *args):    import time    start = time.time()    func(*args)    end = time.time()    print(f'{func.__name__} takes {end - start} seconds')    return end - start# write in 3000 filesdef write_in_5000_files():    for i in range(5000):        with open(f'test/source/{i}.txt', 'w') as f:            f.write('hello world' + os.urandom(24).hex())            f.close()bench_mark(write_in_5000_files)def copy():    shutil.copytree('test/source', 'test/destination')bench_mark(copy)

def _copytree_multithreaded(src, dst, symlinks=false, ignore=none, copy_function=shutil.copy2,                            ignore_dangling_symlinks=false, dirs_exist_ok=false, max_workers=4):    """recursively copy a directory tree using multiple threads."""    sys.audit("shutil.copytree", src, dst)    # get the entries to copy    entries = list(os.scandir(src))    # make the pool    with threadpoolexecutor(max_workers=max_workers) as executor:        # submit the tasks        futures = [            executor.submit(_copytree_single_threaded, entries=[entry], src=src, dst=dst,                            symlinks=symlinks, ignore=ignore, copy_function=copy_function,                            ignore_dangling_symlinks=ignore_dangling_symlinks,                            dirs_exist_ok=dirs_exist_ok)            for entry in entries        ]        # wait for the tasks        for future in as_completed(futures):            try:                future.result()            except exception as e:                print(f"failed to copy: {e}")                raise

if len(entries) >= 100 or sum(os.path.getsize(entry.path) for entry in entries) >= 100*1024*1024:        # multithreaded version        return _copytree_multithreaded(src, dst, symlinks=symlinks, ignore=ignore,                                        copy_function=copy_function,                                        ignore_dangling_symlinks=ignore_dangling_symlinks,                                        dirs_exist_ok=dirs_exist_ok)else:    # single threaded version    return _copytree_single_threaded(entries=entries, src=src, dst=dst,                                        symlinks=symlinks, ignore=ignore,                                        copy_function=copy_function,                                        ignore_dangling_symlinks=ignore_dangling_symlinks,                                        dirs_exist_ok=dirs_exist_ok)

def bench_mark(func, *args):    import time    start = time.perf_counter()    func(*args)    end = time.perf_counter()    print(f"{func.__name__} costs {end - start}s")

import osos.mkdir("test")os.mkdir("test/source")# write in 50000 filesdef write_in_file():    for i in range(50000):         with open(f"test/source/{i}.txt", 'w') as f:             f.write(f"{i}")             f.close()

def copy1():    import shutil    shutil.copytree('test/source', 'test/destination1')def copy2():    import my_shutil    my_shutil.copytree('test/source', 'test/destination2')