public Node parse() throws ScanException {
        if (tokenList == null || tokenList.isEmpty())
            return null;
        return E();
    }
@Test
    public void defaultSeparatorOutsideOfAVariable() throws ScanException {
        Tokenizer tokenizer = new Tokenizer("{a:-b}");
        Parser parser = new Parser(tokenizer.tokenize());
        Node node = parser.parse();

        dump(node);
        Node witness = new Node(Node.Type.LITERAL, "{");
        Node t = witness.next = new Node(Node.Type.LITERAL, "a");

        t.next = new Node(Node.Type.LITERAL, ":-");
        t = t.next;

        t.next = new Node(Node.Type.LITERAL, "b");
        t = t.next;

        t.next = new Node(Node.Type.LITERAL, "}");

        assertEquals(witness, node);
    }