public String transform() throws ScanException {
    StringBuilder stringBuilder = new StringBuilder();
    compileNode(node, stringBuilder, new Stack<Node>());
    return stringBuilder.toString();
  }
@Test
  public void literalVariableLiteral() throws ScanException {
    String input = "a${k0}c";
    Node node = makeNode(input);
    NodeToStringTransformer nodeToStringTransformer = new NodeToStringTransformer(node, propertyContainer0);
    assertEquals("av0c", nodeToStringTransformer.transform());
  }