def collect(cls, block_structure): """ Collects any information that's necessary to execute this transformer's transform method. """ block_structure.request_xblock_fields(*cls.FIELDS_TO_COLLECT) cls._collect_max_scores(block_structure) collect_unioned_set_field( block_structure=block_structure, transformer=cls, merged_field_name='subsections', filter_by=lambda block_key: block_key.block_type == 'sequential', )