class_docstr: A base class for a node in the graph of a workflow.
  
  A node may be an Operator or a Task Group, either mapped or unmapped.
code: def label(self) -> str | None:
      tg = self.task_group
      if tg and tg.node_id and tg.prefix_group_id:
          # "task_group_id.task_id" -> "task_id"
          return self.node_id[len(tg.node_id) + 1 :]
      return self.node_id
  
imports: from __future__ import annotations
  import warnings
  from abc import ABCMeta, abstractmethod
  from typing import TYPE_CHECKING, Any, Iterable, Sequence
  from airflow.exceptions import AirflowException, RemovedInAirflow3Warning
  from airflow.utils.types import NOTSET
label_desc: Use image node_id 2 for calling the DAGNode obj's underlying member method code with example usage: obj.label() and returns: self, self