code: def gen_uid(cls, session_id, name):
      return f"mutable-tensor-{session_id}-{name}"
  
file_path: mars/mars/services/mutable/supervisor/core.py
imports: import asyncio
  from typing import Dict, List, Optional, Tuple, Union
  import numpy
  from ....None import oscar
  from ....core import tile
  from ....utils import build_fetch
  from ...core import NodeRole
  from ...cluster import ClusterAPI
  from ...meta import MetaAPI
  from ..core import MutableTensorInfo
  from ..utils import getitem_to_records, setitem_to_records, normalize_name, normalize_timestamp
  from ..worker import MutableTensorChunkActor
label_desc: Use image node_id 2 for calling the MutableTensorActor obj's underlying member method code with example usage: obj.gen_uid(cls, session_id, name) and returns: str, session_id, str, name