code: def remove_ten_workers(self):
      for i, proc in enumerate(self.worker_process):
          if i == 10:
              break
          os.killpg(os.getpgid(proc.pid), signal.SIGTERM)
  
imports: import unittest
  import parl
  from parl.remote.monitor import ClusterMonitor
  import time
  import threading
  from parl.remote import exceptions
  from parl.utils.test_utils import XparlTestCase
  import os
  import signal
label_desc: Use image node_id 1 for calling the TestClusterMonitor obj's underlying member method code with example usage: obj.remove_ten_workers() without return types