code: def __init__(self, index: int):
      self._index = index
  
file_path: ray/python/ray/workflow/serialization_context.py
imports: import contextlib
  from typing import List, Any, Dict
  from ray.util.serialization import register_serializer, deregister_serializer
  from ray.workflow.common import WorkflowRef
label_desc: Use image node_id 1 to create a new _KeepWorkflowRefs object  with example: obj = _KeepWorkflowRefs(index)