Add test

Author: corona10

Lib/test/test_sys.py

@@ -785,6 +785,15 @@ def __hash__(self):
         self.assertRaises(TypeError, sys.intern, S("abc"))
         self.assertIs(_is_interned(S("abc")), False)
 
+    @support.cpython_only
+    def test_get_object_tags(self):
+        keys = ("immortal", "interned", "deferred_refcount")
+        s = "foobar"
+        tags = sys.get_object_tags(s)
+        self.assertEqual(len(tags), len(keys))
+        for k in keys:
+            self.assertIn(k, tags)
+
     @support.cpython_only
     @requires_subinterpreters
     def test_subinterp_intern_dynamically_allocated(self):