Consolidated test support logic in jaraco.test.cpython.

setup.cfg

@@ -37,7 +37,7 @@ testing =
 	pyfakefs
 	flufl.flake8
 	pytest-perf >= 0.9.2
-	jaraco.collections
+	jaraco.test >= 5.4
 
 docs =
 	# upstream

tests/compat/py39.py

@@ -1,18 +1,6 @@
-import types
+from jaraco.test.cpython import from_test_support, try_import
 
-from jaraco.collections import Projection
 
-
-def from_test_support(*names):
-    """
-    Return a SimpleNamespace of names from test.support.
-    """
-    import test.support
-
-    return types.SimpleNamespace(**Projection(names, vars(test.support)))
-
-
-try:
-    from test.support import os_helper  # type: ignore
-except ImportError:
-    os_helper = from_test_support('FS_NONASCII', 'skip_unless_symlink')
+os_helper = try_import('os_helper') or from_test_support(
+    'FS_NONASCII', 'skip_unless_symlink'
+)