bpo-40275: Use new test.support helper submodules in tests (GH-20849)

diff --git a/Lib/test/test_global.py b/Lib/test/test_global.py
index 8159602..c71d055 100644
--- a/Lib/test/test_global.py
+++ b/Lib/test/test_global.py
@@ -1,6 +1,7 @@
 """Verify that warnings are issued for global statements following use."""
 
-from test.support import run_unittest, check_syntax_error, check_warnings
+from test.support import run_unittest, check_syntax_error
+from test.support.warnings_helper import check_warnings
 import unittest
 import warnings