code: def gen_uid(session_id: str):
      return f"{session_id}_worker_meta"
  
file_path: mars/mars/services/meta/worker/core.py
imports: from typing import Dict
  from ....None import oscar
  from ....lib.aio import alru_cache
  from ...cluster import ClusterAPI
  from ..store import get_meta_store
label_desc: Use image node_id 2 for calling the WorkerMetaStoreActor obj's underlying member method code with example usage: obj.gen_uid(session_id) and returns: session_id, str