code: def down(db, dataset_name):
      match_d = {"name": dataset_name}
      dataset_dict = db.datasets.find_one(match_d)
  
      for field in dataset_dict.get("sample_fields", []):
          if field.get("name", None) == "metadata":
              field[
                  "embedded_doc_type"
              ] = "fiftyone.core.metadata.Metadata"
  
          field.pop("fields", None)
  
      for field in dataset_dict.get("frame_fields", []):
          field.pop("fields", None)
  
      dataset_dict.pop("app_sidebar_groups", None)
  
      db.datasets.replace_one(match_d, dataset_dict)
  
label_desc: Use image node_id 2 for calling a global function with example usage: down(db, dataset_name) without return types