code: def down(self) -> None:
      logging.info(
          "Remove the features field from all the cached results"
      )
      db = get_db(CACHE_MONGOENGINE_ALIAS)
      db[CACHE_COLLECTION_RESPONSES].update_many(
          {
              "kind": "split-duckdb-index",
              "http_status": 200,
          },
          {"$unset": {"content.features": ""}},
      )
  
file_path: datasets-server/jobs/mongodb_migration/src/mongodb_migration/migrations/_20230824154900_cache_add_features_field_in_split_duckdb_index.py
imports: import logging
  from libcommon.constants import CACHE_COLLECTION_RESPONSES, CACHE_MONGOENGINE_ALIAS
  from libcommon.simple_cache import CachedResponseDocument
  from mongoengine.connection import get_db
  from mongodb_migration.check import check_documents
  from mongodb_migration.migration import Migration
label_desc: Use image node_id 2 for calling the MigrationAddFeaturesToSplitDuckdbIndexCacheResponse obj's underlying member method code with example usage: obj.down() without return types