bpo-44771: Apply changes from importlib_resources 5.2.1 (GH-27436)

* bpo-44771: Apply changes from importlib_resources@3b24bd6307

* Add blurb

* Exclude namespacedata01 from eol conversion.

Lib/test/test_importlib/test_contents.py

@@ -0,0 +1,42 @@
+import unittest
+from importlib import resources
+
+from . import data01
+from .resources import util
+
+
+class ContentsTests:
+    expected = {
+        '__init__.py',
+        'binary.file',
+        'subdirectory',
+        'utf-16.file',
+        'utf-8.file',
+    }
+
+    def test_contents(self):
+        assert self.expected <= set(resources.contents(self.data))
+
+
+class ContentsDiskTests(ContentsTests, unittest.TestCase):
+    def setUp(self):
+        self.data = data01
+
+
+class ContentsZipTests(ContentsTests, util.ZipSetup, unittest.TestCase):
+    pass
+
+
+class ContentsNamespaceTests(ContentsTests, unittest.TestCase):
+    expected = {
+        # no __init__ because of namespace design
+        # no subdirectory as incidental difference in fixture
+        'binary.file',
+        'utf-16.file',
+        'utf-8.file',
+    }
+
+    def setUp(self):
+        from . import namespacedata01
+
+        self.data = namespacedata01