public String transform() throws ScanException {
        StringBuilder stringBuilder = new StringBuilder();
        compileNode(node, stringBuilder, new Stack<Node>());
        return stringBuilder.toString();
    }
@Test
    public void withDefaultValue() throws ScanException {
        String input = "${k67:-b}c";
        Node node = makeNode(input);
        NodeToStringTransformer nodeToStringTransformer = new NodeToStringTransformer(node, propertyContainer0);
        Assertions.assertEquals("bc", nodeToStringTransformer.transform());
    }