code: def _get_ext_index_type(index_obj):
      import cudf
  
      multi_index_type = None
      if isinstance(index_obj, pd.MultiIndex):
          multi_index_type = "pandas"
      elif isinstance(index_obj, cudf.MultiIndex):
          multi_index_type = "cudf"
  
      if multi_index_type is None:
          return None
      return {
          "index_type": multi_index_type,
          "names": list(index_obj.names),
      }
  
file_path: mars/mars/serialization/cuda.py
imports: from typing import Any, List, Dict, Tuple
  import pandas
  from ..utils import lazy_import
  from .core import Serializer, buffered
label_desc: Use image node_id 1 for calling the CudfSerializer obj's underlying member method code with example usage: obj._get_ext_index_type(index_obj) and returns: dict, None