code: def test_serialize(self, session):
      dagrun_model_1 = DagRun(
          dag_id="my-dag-run",
          run_id="my-dag-run",
          state="running",
          execution_date=timezone.parse(self.default_time),
          run_type=DagRunType.MANUAL.value,
          start_date=timezone.parse(self.default_time),
          conf='{"start": "stop"}',
      )
      dagrun_model_2 = DagRun(
          dag_id="my-dag-run",
          run_id="my-dag-run-2",
          state="running",
          execution_date=timezone.parse(self.second_time),
          start_date=timezone.parse(self.default_time),
          run_type=DagRunType.MANUAL.value,
      )
      dagruns = [dagrun_model_1, dagrun_model_2]
      session.add_all(dagruns)
      session.commit()
      instance = DAGRunCollection(dag_runs=dagruns, total_entries=2)
      deserialized_dagruns = dagrun_collection_schema.dump(instance)
      assert deserialized_dagruns == {
          "dag_runs": [
              {
                  "dag_id": "my-dag-run",
                  "dag_run_id": "my-dag-run",
                  "end_date": None,
                  "execution_date": self.default_time,
                  "logical_date": self.default_time,
                  "external_trigger": True,
                  "state": "running",
                  "start_date": self.default_time,
                  "conf": {"start": "stop"},
                  "data_interval_end": None,
                  "data_interval_start": None,
                  "last_scheduling_decision": None,
                  "run_type": "manual",
                  "note": None,
              },
              {
                  "dag_id": "my-dag-run",
                  "dag_run_id": "my-dag-run-2",
                  "end_date": None,
                  "state": "running",
                  "execution_date": self.second_time,
                  "logical_date": self.second_time,
                  "external_trigger": True,
                  "start_date": self.default_time,
                  "conf": {},
                  "data_interval_end": None,
                  "data_interval_start": None,
                  "last_scheduling_decision": None,
                  "run_type": "manual",
                  "note": None,
              },
          ],
          "total_entries": 2,
      }
  
imports: from __future__ import annotations
  import pytest
  from dateutil.parser import parse
  from airflow.api_connexion.exceptions import BadRequest
  from airflow.api_connexion.schemas.dag_run_schema import DAGRunCollection, dagrun_collection_schema, dagrun_schema
  from airflow.models import DagRun
  from airflow.utils import timezone
  from airflow.utils.session import provide_session
  from airflow.utils.types import DagRunType
  from tests.test_utils.db import clear_db_runs
label_desc: Use image node_id 1 for calling the TestDagRunCollection obj's underlying member method code with example usage: obj.test_serialize(session) without return types