code: def start_killing(self):
      time.sleep(self.warmup_time_s)
      while True:
          if random.random() < self.probability:
              self.kill()
          time.sleep(self.time_between_checks_s)
  
file_path: ray/release/tune_tests/fault_tolerance_tests/workloads/terminate_node_aws.py
imports: import subprocess
  import random
  import requests
  import time
  import logging
  import ray
  from ray.util.scheduling_strategies import NodeAffinitySchedulingStrategy
  from ray._private.test_utils import safe_write_to_results_json
label_desc: Use image node_id 2 for calling the InstanceKillerActor obj's underlying member method code with example usage: obj.start_killing() without return types