code: def test_from_json(self, input, request_class):
      if input is None:
          ti = TaskInstance(
              task=BashOperator(
                  task_id="test",
                  bash_command="true",
                  dag=DAG(dag_id="id"),
                  start_date=datetime.now(),
              ),
              run_id="fake_run",
              state=State.RUNNING,
          )
  
          input = TaskCallbackRequest(
              full_filepath="filepath",
              simple_task_instance=SimpleTaskInstance.from_ti(ti=ti),
              processor_subdir="/test_dir",
              is_failure_callback=True,
          )
      json_str = input.to_json()
      result = request_class.from_json(json_str=json_str)
      assert result == input
  
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 1 for calling the TestCallbackRequest obj's underlying member method code with example usage: obj.test_from_json(input, request_class) without return types