Issue #7818: set().test_c_api() doesn't expect a set('abc'), modify the set.
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index 32f2803..808cf27 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -562,7 +562,7 @@
     # C API test only available in a debug build
     if hasattr(set, "test_c_api"):
         def test_c_api(self):
-            self.assertEqual(set('abc').test_c_api(), True)
+            self.assertEqual(set().test_c_api(), True)
 
 class SetSubclass(set):
     pass