def METHOD_NAME(self, is_within_directory_patch, tarfile_open_patch):
    stream_str = io.BytesIO(b"Hello World!")
    unpack_dir = "/test_unpack_dir/"
    is_within_directory_patch.return_value = True
    tarfile_file_mock = Mock()  # Mock tarfile
    tar_file_obj_mock = Mock()  # Mock member inside tarfile
    tar_file_obj_mock.name = "obj_name"
    tarfile_file_mock.getmembers.return_value = [tar_file_obj_mock]
    tarfile_open_patch.return_value.__enter__.return_value = tarfile_file_mock
    extract_tarfile(file_obj=stream_str, unpack_dir=unpack_dir)
    is_within_directory_patch.assert_called_once()
    tarfile_file_mock.getmembers.assert_called_once()
    tarfile_file_mock.extractall.assert_called_once_with(unpack_dir)