code: def kill_master(self) -> None:
      self.dc.kill_stage("master")
  
imports: import json
  import os
  import subprocess
  import time
  from typing import Any, Dict, Iterator, List, Union, cast
  import pytest
  from tests import config
  from .abstract_cluster import Cluster
  from .test_users import logged_in_user
  from .utils import now_ts, set_master_port
label_desc: Use image node_id 5 for calling the ManagedCluster obj's underlying member method code with example usage: obj.kill_master() without return types