def _load_batch_actions(
        self,
        attrs,
        resource_name,
        collection_model,
        service_model,
        event_emitter,
    ):
        """
        Batch actions on the collection become methods on both
        the collection manager and iterators.
        """
        for action_model in collection_model.batch_actions:
            snake_cased = xform_name(action_model.name)
            attrs[snake_cased] = self._create_batch_action(
                resource_name,
                snake_cased,
                action_model,
                collection_model,
                service_model,
                event_emitter,
            )

        Batch actions on the collection become methods on both
        the collection manager and iterators.
        
boto3/resources/collection.py