class_docstr: Represents a version of a DAG and becomes a source of truth for a BackfillJob execution.
  
  Dags can originate from different places (user repos, main repo, ...) and also get executed
  in different places (different executors).  A pickle is a native python serialized object,
  and in this case gets stored in the database for the duration of the job.
  
  The executors pick up the DagPickle id and read the dag definition from the database.
code: def __init__(self, dag: DAG) -> None:
      self.dag_id = dag.dag_id
      if hasattr(dag, "template_env"):
          dag.template_env = None  # type: ignore[attr-defined]
      self.pickle_hash = hash(dag)
      self.pickle = dag
  
file_path: airflow/airflow/models/dagpickle.py
imports: from __future__ import annotations
  from typing import TYPE_CHECKING
  import dill
  from sqlalchemy import BigInteger, Column, Integer, PickleType
  from airflow.models.base import Base
  from airflow.utils import timezone
  from airflow.utils.sqlalchemy import UtcDateTime
label_desc: Use image node_id 1 to create a new DagPickle object from inherited base classes: Base with example: obj = DagPickle(dag)