code: def test_empty_iterable(self):
      p = self.Pool(1)
  
      self.assertEqual(p.map(sqr, []), [])
      self.assertEqual(list(p.imap(sqr, [])), [])
      self.assertEqual(list(p.imap_unordered(sqr, [])), [])
  
      self.assertEqual(p.starmap(sqr, []), [])
      self.assertEqual(list(p.istarmap(sqr, [])), [])
      self.assertEqual(list(p.istarmap_unordered(sqr, [])), [])
  
      self.assertEqual(p.map_async(sqr, []).get(), [])
      self.assertEqual(p.starmap_async(mul, []).get(), [])
  
      p.close()
      p.join()
  
imports: from mpi4py import MPI
  import mpi4py.util.pool
  import concurrent.futures
  import itertools
  import functools
  import warnings
  import unittest
  import time
  import sys
  import os
label_desc: Use image node_id 17 for calling the BaseTestPool obj's underlying member method code with example usage: obj.test_empty_iterable() without return types