code: def get_nodes_info(self, *args, **kwargs):
      return self._node_infos
  
file_path: mars/mars/services/cluster/tests/test_locator.py
imports: import asyncio
  import os
  import tempfile
  from typing import List
  import pytest
  from ....None import oscar
  from ....utils import Timer
  from ....tests.core import flaky
  from ..core import NodeRole, NodeStatus
  from ..supervisor.locator import SupervisorPeerLocatorActor
  from ..supervisor.node_info import NodeInfoCollectorActor
  from ..tests import backend
  from ..worker.locator import WorkerSupervisorLocatorActor
label_desc: Use image node_id 3 for calling the MockNodeInfoCollectorActor obj's underlying member method code with example usage: obj.get_nodes_info() and returns: self