code: def stop_spark_standalone():
      import subprocess
  
      env = SparkRunner.standalone_env
      if env is not None:
          stop_worker_pro = subprocess.Popen(
              "{}/sbin/stop-worker.sh".format(
                  env["ZOO_STANDALONE_HOME"]
              ),
              shell=True,
              env=env,
          )
          os.waitpid(stop_worker_pro.pid, 0)
          stop_master_pro = subprocess.Popen(
              "{}/sbin/stop-master.sh".format(
                  env["ZOO_STANDALONE_HOME"]
              ),
              shell=True,
              env=env,
          )
          os.waitpid(stop_master_pro.pid, 0)
      else:
          # if env is None, then the standalone cluster is not started by BigDL
          pass
  
imports: import os
  import sys
  import random
  import platform
  from pyspark import SparkContext
  from bigdl.dllib.nncontext import init_internal_nncontext, init_spark_conf
  from bigdl.dllib.utils.utils import detect_python_location, pack_penv, get_node_ip
  from bigdl.dllib.utils.utils import get_executor_conda_zoo_classpath
  from bigdl.dllib.utils.utils import get_zoo_bigdl_classpath_on_driver
  from bigdl.dllib.utils.utils import get_bigdl_class_version
  from bigdl.dllib.utils.utils import get_bigdl_image_workdir
  from bigdl.dllib.utils.utils import is_valid_ip_address
  from bigdl.dllib.utils.engine import get_bigdl_jars
  from bigdl.dllib.utils.log4Error import *
label_desc: Use image node_id 7 for calling the SparkRunner obj's underlying member method code with example usage: obj.stop_spark_standalone() without return types