HierarchicalStreamWriter writer = new PrettyPrintWriter(buffer);
writer.startNode("people");
xstream.marshal(new Person("Postman", "Pat"), writer);
xstream.marshal(new Person("Bob", "Builder"), writer);
xstream.marshal(new Person("Tinky", "Winky"), writer);
writer.endNode();
assertEquals(""
+ "<people>\n"
+ " <person>\n"
+ " <firstName>Postman</firstName>\n"