@classmethod
def _add_to_database(cls, database):
    cell_data = database.add_class('Cell', cls)
    cell_data.add_attribute('coordinates', shape=(2,), dtype=np.int32)
    cell_data.add_attribute('alive', False, dtype=np.bool)
    cell_data.add_connectivity_matrix('neighbors', 'Cell')
    return cell_data.get_instance_type()
@classmethod
def _add_to_database(cls, database):
    cell_data = database.add_class('Cell', cls)
    cell_data.add_attribute('coordinates', shape=(2,), dtype=np.int32)
    cell_data.add_attribute('alive', False, dtype=np.bool)
    cell_data.add_connectivity_matrix('neighbors', 'Cell')
    return cell_data.get_instance_type()