code: def time_since_last_state_change(self) -> int:
      return time_msecs() - self.last_state_change_timestamp_msecs
  
imports: import abc
  import logging
  from typing import Any, List, Tuple
  from hailtop.utils import time_msecs
  from ..file_store import FileStore
  from ..instance_config import InstanceConfig, QuantifiedResource
  from .instance import Instance
label_desc: Use image node_id 2 for calling the TimestampedVMState obj's underlying member method code with example usage: obj.time_since_last_state_change() and returns: unknown