code: def test_notifier(self, mock_opsgenie_alert_hook, dag_maker):
      with dag_maker("test_notifier") as dag:
          EmptyOperator(task_id="task1")
      notifier = send_opsgenie_notification(payload=self._config)
      notifier({"dag": dag})
      mock_opsgenie_alert_hook.return_value.create_alert.assert_called_once_with(
          self.expected_payload_dict
      )
  
file_path: airflow/tests/providers/opsgenie/notifications/test_opsgenie.py
imports: from __future__ import annotations
  from unittest import mock
  import pytest
  from airflow.operators.empty import EmptyOperator
  from airflow.providers.opsgenie.hooks.opsgenie import OpsgenieAlertHook
  from airflow.providers.opsgenie.notifications.opsgenie import OpsgenieNotifier, send_opsgenie_notification
label_desc: Use image node_id 1 for calling the TestOpsgenieNotifier obj's underlying member method code with example usage: obj.test_notifier(mock_opsgenie_alert_hook, dag_maker) without return types