code: def __bool__(self) -> bool:
      return bool(self.node_availabilities)
  
file_path: ray/python/ray/autoscaler/_private/node_provider_availability_tracker.py
imports: import threading
  import time
  from dataclasses import dataclass
  from typing import Callable, Dict, Optional, Tuple
  from ray.autoscaler._private.constants import AUTOSCALER_NODE_AVAILABILITY_MAX_STALENESS_S
  from ray.autoscaler.node_launch_exception import NodeLaunchException
label_desc: Use image node_id 3 for calling the NodeAvailabilitySummary obj's underlying member method code with example usage: obj.__bool__() and returns: bool