Return true if given class supports back up. Currently this means a
    gludb.data.Storable-derived class that has a mapping as defined in
    gludb.config

def is_backup_class(cls):
    """Return true if given class supports back up. Currently this means a
    gludb.data.Storable-derived class that has a mapping as defined in
    gludb.config"""
    return True if (
        isclass(cls) and
        issubclass(cls, Storable) and
        get_mapping(cls, no_mapping_ok=True)
    ) else False