code: def test_prepare_template(self):
      report = {"key": "value"}
      with NamedTemporaryFile("w+", suffix=".json") as f:
          f.write(json.dumps(report))
          f.flush()
          op = GoogleSearchAdsInsertReportOperator(
              report=report,
              api_version=API_VERSION,
              task_id="test_task",
          )
          op.prepare_template()
  
      assert isinstance(op.report, dict)
      assert op.report == report
  
file_path: airflow/tests/providers/google/marketing_platform/operators/test_search_ads.py
imports: from __future__ import annotations
  import json
  from tempfile import NamedTemporaryFile
  from unittest import mock
  import pytest
  from airflow.models import DAG, TaskInstance
  from airflow.providers.google.marketing_platform.operators.search_ads import GoogleSearchAdsDownloadReportOperator, GoogleSearchAdsInsertReportOperator
  from airflow.utils import timezone
  from airflow.utils.session import create_session
label_desc: Use image node_id 2 for calling the TestGoogleSearchAdsInsertReportOperator obj's underlying member method code with example usage: obj.test_prepare_template() without return types