code: def test_local(self):
      node_num = 4
      sc = init_spark_on_local(cores=node_num)
      ray_ctx = OrcaRayContext(sc=sc, object_store_memory="1g")
      ray_ctx.init()
      actors = [TestRay.remote() for i in range(0, node_num)]
      print(ray.get([actor.hostname.remote() for actor in actors]))
      ray_ctx.stop()
      time.sleep(3)
      # repeat
      print("-------------------first repeat begin!------------------")
      ray_ctx = OrcaRayContext(sc=sc, object_store_memory="1g")
      ray_ctx.init()
      actors = [TestRay.remote() for i in range(0, node_num)]
      print(ray.get([actor.hostname.remote() for actor in actors]))
      ray_ctx.stop()
      sc.stop()
      time.sleep(3)
  
file_path: BigDL/python/orca/test/bigdl/orca/ray/test_reinit_raycontext.py
imports: import time
  from unittest import TestCase
  import numpy
  import psutil
  import pytest
  import ray
  from bigdl.dllib.nncontext import init_spark_on_local
  from bigdl.orca.ray import OrcaRayContext
label_desc: Use image node_id 1 for calling the TestUtil obj's underlying member method code with example usage: obj.test_local() without return types