tests/test-check-interfaces.py

--- a/tests/test-check-interfaces.py	Mon Feb 15 13:59:36 2021 -0500
+++ b/tests/test-check-interfaces.py	Mon Feb 15 14:11:38 2021 -0500
@@ -113,6 +113,10 @@
     def close(self):
         pass
 
+    @property
+    def closed(self):
+        pass
+
 
 def main():
     ui = uimod.ui()