code: def test_taskcallback_to_json_with_start_date_and_end_date(
      self, session, create_task_instance
  ):
      ti = create_task_instance()
      ti.start_date = timezone.utcnow()
      ti.end_date = timezone.utcnow()
      session.merge(ti)
      session.flush()
      input = TaskCallbackRequest(
          full_filepath="filepath",
          simple_task_instance=SimpleTaskInstance.from_ti(ti),
          processor_subdir="/test_dir",
          is_failure_callback=True,
      )
      json_str = input.to_json()
      result = TaskCallbackRequest.from_json(json_str)
      assert input == result
  
file_path: airflow/tests/callbacks/test_callback_requests.py
imports: from __future__ import annotations
  from datetime import datetime
  import pytest
  from airflow.callbacks.callback_requests import CallbackRequest, DagCallbackRequest, SlaCallbackRequest, TaskCallbackRequest
  from airflow.models.dag import DAG
  from airflow.models.taskinstance import SimpleTaskInstance, TaskInstance
  from airflow.operators.bash import BashOperator
  from airflow.utils import timezone
  from airflow.utils.state import State
label_desc: Use image node_id 2 for calling the TestCallbackRequest obj's underlying member method code with example usage: obj.test_taskcallback_to_json_with_start_date_and_end_date(session, create_task_instance) without return types