def _proto_dataset_info(dataset):
    """Return information about proto dataset as a dict."""
    # Analogous to dtool_info.inventory._dataset_info
    info = {}

    info['type'] = 'dtool-proto'

    info['uri'] = dataset.uri

    info['uuid'] = dataset.uuid

    info["size_int"] = None
    info["size_str"] = 'unknown'

    info['creator'] = dataset._admin_metadata['creator_username']
    info['name'] = dataset._admin_metadata['name']

    info["date"] = 'not yet frozen'

    info['readme_content'] = dataset.get_readme_content()

    return info