code: def _get_node(instance_id: int, node_index: int) -> SourceType:
      """Get the node instance.
  
      Note: This function should be static and globally importable,
      otherwise the serialization overhead would be very significant.
      """
      return _instances[instance_id]._replace_index(node_index)
  
file_path: ray/python/ray/dag/py_obj_scanner.py
imports: import io
  from typing import Any, Dict, Generic, List, Tuple, Type, TypeVar, Union
  import pickle
  import ray
  from ray.dag.base import DAGNodeBase
label_desc: Use image node_id 1 for calling a global function with example usage: _get_node(instance_id, node_index) and returns: _instances