code: def test_close_session_on_active_session(self):
      session_id = self.connect_session()
      session_info = self.session_mgr.get_session_info(session_id)
      self.session_mgr.close_session(session_id)
  
      assert (
          session_id not in self.session_mgr._active_session_info_by_id
      )
      assert session_id not in self.session_mgr._session_storage._cache
      session_info.session.shutdown.assert_called_once()
  
imports: import unittest
  from unittest.mock import MagicMock, patch
  import pytest
  from streamlit.runtime.script_data import ScriptData
  from streamlit.runtime.session_manager import SessionStorage
  from streamlit.runtime.websocket_session_manager import WebsocketSessionManager
label_desc: Use image node_id 18 for calling the WebsocketSessionManagerTests obj's underlying member method code with example usage: obj.test_close_session_on_active_session() without return types