def demo_to_dict(demo):
    """
    Convert an instance of the Demo model to a dict.

    :param demo:  An instance of the Demo model.
    :return:      A dict representing the demo.
    """
    return {
        'id': demo.id,
        'name': demo.name,
        'guid': demo.guid,
        'createdAt': demo.createdAt,
        'users': demo.users
    }