code: def test_backcompat_prefix_works(self, uri):
      with patch.dict(os.environ, {"AIRFLOW_CONN_MY_CONN": uri}):
          hook = YandexCloudBaseHook("my_conn")
          assert hook.default_folder_id == "abc"
          assert hook.default_public_ssh_key == "abc"
  
file_path: airflow/tests/providers/yandex/hooks/test_yandex.py
imports: from __future__ import annotations
  import os
  from unittest import mock
  from unittest.mock import MagicMock, patch
  import pytest
  from airflow.exceptions import AirflowException
  from airflow.providers.yandex.hooks.yandex import YandexCloudBaseHook
  from tests.test_utils.config import conf_vars
label_desc: Use image node_id 7 for calling the TestYandexHook obj's underlying member method code with example usage: obj.test_backcompat_prefix_works(uri) without return types