code: def gen_uid(session_id: str):
      return f"{session_id}_meta"
  
file_path: mars/mars/services/meta/supervisor/core.py
imports: import asyncio
  from typing import Dict
  from ....None import oscar
  from ...session import SessionAPI
  from ..store import get_meta_store
label_desc: Use image node_id 3 for calling the MetaStoreActor obj's underlying member method code with example usage: obj.gen_uid(session_id) and returns: session_id, str