code: def testPoolWithClause(self):
      ctx = multiprocessing.get_context()
      with ctx.Pool(3) as p:
          res = p.map(pickleable_sqr, [1, 2, 3, 4])
      self.assertEqual(res, [1, 4, 9, 16])
  
file_path: agents/tf_agents/system/multiprocessing_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import pickle
  from tf_agents.system import system_multiprocessing
  from tf_agents.utils import test_utils
label_desc: Use image node_id 3 for calling the MultiprocessingTest obj's underlying member method code with example usage: obj.testPoolWithClause() without return types