code: def __init__(self, session_id: str):
      self._session_id = session_id
      self._cluster_api: Optional[ClusterAPI] = None
  
      self._mutable_objects = dict()
  
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 1 to create a new MutableObjectManagerActor object from inherited base classes: mo with example: obj = MutableObjectManagerActor(session_id)