def _build_containerized_extractors(cls, containers, container_annos,
                                        template, tree):
        """
        Convert container annotation trees into container extractors.
        """
        container_extractors = []
        for container_name, container_data in tree.items():
            if container_name not in containers:
                continue  # Ignore missing containers
            container = container_annos[container_name]
            annotation = None
            for a in template.annotations:
                if a.metadata.get('id') == container_name:
                    annotation = a
                    break
            if container:
                cls._add_new_container(
                    annotation, container_extractors, container_data,
                    template, container_annos, container)
        return container_extractors

        Convert container annotation trees into container extractors.
        
slybot/slybot/plugins/scrapely_annotations/extraction/container_extractors.py