Split Addition into Insertion and Append.
diff --git a/rackspace/cdn/v1/services/delegate_test.go b/rackspace/cdn/v1/services/delegate_test.go
index 8a2a2ba..e2ebb00 100644
--- a/rackspace/cdn/v1/services/delegate_test.go
+++ b/rackspace/cdn/v1/services/delegate_test.go
@@ -308,7 +308,7 @@
 			},
 			Index: 0,
 		},
-		os.Addition{
+		os.Append{
 			Value: os.Domain{Domain: "added.mocksite4.com"},
 		},
 	}