def METHOD_NAME(mocker):
    paths = [str(i) for i in range(10)]
    mocker.patch("os.listdir", return_value=paths)
    mocker.patch("os.path.isdir", return_value=False)
    mocker.patch.object(files, "is_image", return_value=True)
    assert files.get_size_directory("any") == "10"