List<PartsLexer.Part> parts = new ArrayList<PartsLexer.Part>();
parts.add(PartFactory.parse(".field0",1));
PartsParser parser = new PartsParser(parts);
String jn = parser.treeFields();
assertEquals("field0", jn);
assertEquals(parser.last().getName(), "field0");
assertEquals(parser.lastParent().getName(), "field0");
assertEquals(parser.first().getName(), "field0");
}