code: def _populate_db(self):
      session = Session()
      session.query(DagRun).delete()
      session.query(TaskInstance).delete()
      session.commit()
      session.close()
  
      dagbag = DagBag(
          include_examples=True,
          dag_folder=self.PAPERMILL_EXAMPLE_DAGS,
      )
      for dag in dagbag.dags.values():
          dag.sync_to_db()
          SerializedDagModel.write_dag(dag)
  
imports: from __future__ import annotations
  import json
  import os
  import re
  from datetime import timedelta
  from unittest import mock
  from urllib.parse import quote_plus
  import pytest
  from airflow import settings
  from airflow.api.common.experimental.trigger_dag import trigger_dag
  from airflow.models import DagBag, DagRun, Pool, TaskInstance
  from airflow.models.serialized_dag import SerializedDagModel
  from airflow.settings import Session
  from airflow.utils.timezone import datetime, parse, utcnow
  from airflow.version import version
  from tests.test_utils.db import clear_db_pools
label_desc: Use image node_id 1 for calling the TestLineageApiExperimental obj's underlying member method code with example usage: obj._populate_db() without return types