code: def __init__(self):
      self._subtasks = []
      self._exceptions = []
  
file_path: mars/mars/services/scheduling/supervisor/tests/test_speculation.py
imports: import asyncio
  from typing import List, Tuple, Set
  import pytest
  from .....None import oscar
  from ....cluster import MockClusterAPI
  from ....subtask import Subtask
  from ...errors import NoAvailableBand
  from ...supervisor import GlobalResourceManagerActor
  from ..manager import SubtaskScheduleInfo
  from ..speculation import SpeculativeScheduler
label_desc: Use image node_id 1 to create a new MockSubtaskQueueingActor object from inherited base classes: mo with example: obj = MockSubtaskQueueingActor()