Suggestion

arkindex/users/utils.py

@@ -7,7 +7,10 @@ PUBLIC_LEVEL = Role.Guest.value
 
 
 def has_public_field(model):
-    return type(getattr(model, 'public', None)) is DeferredAttribute
+    return isinstance(
+        getattr(model, 'public', None),
+        DeferredAttribute
+    )
 
 
 def get_public_instances(model):