public Node parse() throws ScanException {
        return E();
    }
@Test
    public void keywordGluedToLitteral() throws Exception {
        Parser<Object> p = new Parser<>("%x{}a");
        Node t = p.parse();
        SimpleKeywordNode witness = new SimpleKeywordNode("x");
        witness.setOptions(new ArrayList<String>());
        witness.next = new Node(Node.LITERAL, "a");
        Assertions.assertEquals(witness, t);
    }