diff --git a/samples/api-python-client-doc/main.py b/samples/api-python-client-doc/main.py
index 2e9fa8d..afce74d 100755
--- a/samples/api-python-client-doc/main.py
+++ b/samples/api-python-client-doc/main.py
@@ -88,7 +88,8 @@
 
     collections = []
     for name in dir(service):
-      if not "_" in name and callable(getattr(service, name)):
+      if not "_" in name and callable(getattr(service, name)) and hasattr(
+            getattr(service, name), '__is_resource__'):
         collections.append(name)
 
     for name in collections: