def metadata_item_format(value):
    """Space-separated values in 'key=value' format."""
    try:
        data_name, data_value = value.split('=')
    except ValueError:
        message = (
            'Incorrectly formatted metadata. Argument values should be in the format a=b c=d'
            )
        raise ValueError(message)
    return {'name': data_name, 'value': data_value}
