class_docstr: Type containing data related to an AppSession.
  
  For each AppSession, the Runtime tracks that session's
  script_run_count. This is used to track the age of messages in
  the ForwardMsgCache.
code: def is_active(self) -> bool:
      return self.client is not None
  
imports: from abc import abstractmethod
  from dataclasses import dataclass
  from typing import Callable, Dict, List, Optional, cast
  from typing_extensions import Protocol
  from streamlit.proto.ForwardMsg_pb2 import ForwardMsg
  from streamlit.runtime.app_session import AppSession
  from streamlit.runtime.script_data import ScriptData
  from streamlit.runtime.scriptrunner.script_cache import ScriptCache
  from streamlit.runtime.uploaded_file_manager import UploadedFileManager
label_desc: Use image node_id 1 for calling the SessionInfo obj's underlying member method code with example usage: obj.is_active() and returns: unknown