bpo-40275: Use new test.support helper submodules in tests (GH-21314)

diff --git a/Lib/test/test_heapq.py b/Lib/test/test_heapq.py
index 6902573..ebbc627 100644
--- a/Lib/test/test_heapq.py
+++ b/Lib/test/test_heapq.py
@@ -5,11 +5,12 @@
 import doctest
 
 from test import support
+from test.support import import_helper
 from unittest import TestCase, skipUnless
 from operator import itemgetter
 
-py_heapq = support.import_fresh_module('heapq', blocked=['_heapq'])
-c_heapq = support.import_fresh_module('heapq', fresh=['_heapq'])
+py_heapq = import_helper.import_fresh_module('heapq', blocked=['_heapq'])
+c_heapq = import_helper.import_fresh_module('heapq', fresh=['_heapq'])
 
 # _heapq.nlargest/nsmallest are saved in heapq._nlargest/_smallest when
 # _heapq is imported, so check them there