public Node parse() throws ScanException {
        return E();
    }
@Test
    public void testNested() throws Exception {
        {
            Parser<Object> p = new Parser<>("%top %(%child%(%h))");
            Node t = p.parse();
            Node witness = new SimpleKeywordNode("top");
            Node w = witness.next = new Node(Node.LITERAL, " ");
            CompositeNode composite = new CompositeNode(BARE);
            w = w.next = composite;
            Node child = new SimpleKeywordNode("child");
            composite.setChildNode(child);
            composite = new CompositeNode(BARE);
            child.next = composite;
            composite.setChildNode(new SimpleKeywordNode("h"));

            Assertions.assertEquals(witness, t);
        }
    }