public void marshal(Object source, HierarchicalStreamWriter writer,
                        MarshallingContext context) {
        Object collection = source;

        if (source instanceof PersistentCollection) {
            PersistentCollection col = (PersistentCollection)source;
            col.forceInitialization();
            collection = col.getCollectionSnapshot().getSnapshot();
        }

        // the set is returned as a map by Hibernate (unclear why exactly)
        if (source instanceof PersistentSet) {
            collection = new HashSet(((HashMap)collection).values());
        }

        // delegate the collection to the approapriate converter
        if (listSetConverter.canConvert(collection.getClass())) {
            listSetConverter.marshal(collection, writer, context);
            return;
        }
        if (mapConverter.canConvert(collection.getClass())) {
            mapConverter.marshal(collection, writer, context);
            return;
        }
        if (treeMapConverter.canConvert(collection.getClass())) {
            treeMapConverter.marshal(collection, writer, context);
            return;
        }
        if (treeSetConverter.canConvert(collection.getClass())) {
            treeSetConverter.marshal(collection, writer, context);
            return;
        }

        defaultConverter.marshal(collection, writer, context);
    }