Add more test on Optionnal, Required children serialization

xmpp-parsers/src/muc/muc.rs

@@ -191,4 +191,9 @@ mod tests {
             DateTime::from_str("1970-01-01T00:00:00+00:00").unwrap()
         );
     }
+
+    #[test]
+    fn test_serialize_muc_history() {
+        assert!(false);
+    }
 }

xmpp-parsers/src/muc/user.rs

@@ -687,4 +687,9 @@ mod tests {
             Item { reason, .. } => assert_eq!(reason, Some(Reason("foobar".to_owned()))),
         }
     }
+
+    #[test]
+    fn test_serialize_item() {
+        assert!(false);
+    }
 }