async def METHOD_NAME(directory_client, num_child_files):
    import itertools
    # Use a thread pool because it is too slow otherwise
    async def create_file():
        # generate a random name
        file_name = str(uuid.uuid4()).replace('-', '')
        file_client = directory_client.get_file_client(file_name)
        await file_client.create_file()
    futures = [asyncio.ensure_future(create_file()) for _ in itertools.repeat(None, num_child_files)]
    await asyncio.wait(futures)
    print("Created {} files under the directory '{}'.".format(num_child_files, directory_client.path_name))