@classmethod
    def clean_up(self):
        num_of_items_deleted = pm.mel.eval('MLdeleteUnused')

        logger.debug('deleting unknown references')
        delete_nodes_types = ['reference', 'unknown']
        for node in pm.ls(type=delete_nodes_types):
            node.unlock()

        logger.debug('deleting "delete_nodes_types"')
        try:
            pm.delete(pm.ls(type=delete_nodes_types))
        except RuntimeError:
            pass
cleans up the scene
dataset/ETHPy150Open eoyilmaz/anima/anima/env/mayaEnv/repr_tools.py/RepresentationGenerator.clean_up