class_docstr: Wraps the normal Ray DAGNode with some metadata.
class_docstr_tok: ["Wraps","the","normal","Ray","DAGNode","with","some","metadata","."]
docstr: Args:
      idx: A unique index into the original DAG.
      dag_node: The original DAG node created by the user.
docstr_tok: ["Args",":","idx",":","A","unique","index","into","the","original","DAG",".","dag_node",":","The","original","DAG","node","created","by","the","user","."]
code: def __init__(self, idx: int, dag_node: "ray.dag.DAGNode"):
      """
      Args:
          idx: A unique index into the original DAG.
          dag_node: The original DAG node created by the user.
      """
      self.idx = idx
      self.dag_node = dag_node
  
      self.downstream_node_idxs = set()
      self.output_channel = None
  
imports: from collections import defaultdict
  from typing import Any, Dict, List, Tuple, Union, Optional
  import logging
  import threading
  import traceback
  import ray
  from ray.exceptions import RayTaskError
  from ray.experimental.channel import Channel
  from ray.util.annotations import DeveloperAPI
label_desc: Use image node_id 1 to create a new CompiledTask object  with example: obj = CompiledTask(idx, dag_node)