def METHOD_NAME(dataset):
    import unittest.mock as mock
    with mock.patch.object(dataset.client,
                           'upload_data',
                           wraps=dataset.client.upload_data) as upload_data_spy:
        dataset._create_descriptor_file(items=[{'row_data': 'some text...'}])
        upload_data_spy.assert_called()
        call_args, call_kwargs = upload_data_spy.call_args_list[0][
            0], upload_data_spy.call_args_list[0][1]
        assert call_args == ('[{"row_data": "some text..."}]',)
        assert call_kwargs == {
            'content_type': 'application/json',
            'filename': 'json_import.json'
        }