'string', 'creative_features_spec' => 'AdCreativeFeaturesSpec', 'degrees_of_freedom_type' => 'string', 'image_transformation_types' => 'list', 'multi_media_transformation_type' => 'string', 'stories_transformation_types' => 'list', 'text_transformation_types' => 'list', 'video_transformation_types' => 'list', ); } }