
![image](https://user-images.githubusercontent.com/12162539/50417924-d6cc2b80-0863-11e9-860f-bf9d132db570.png)

private static final String STEP_FIRST_CHAR = "`---";
    private static final String STEP_NORMAL_CHAR = "+---";
    private static final String STEP_HAS_BOARD = "|   ";
    private static final String STEP_EMPTY_BOARD = "    ";
    
    private final boolean isPrintCost;
    
    private final Node root;
    
    private Node current;
    public TTree(boolean isPrintCost, String title) {
        this.root = new Node(title).markBegin().markEnd();
        this.current = root;
        this.isPrintCost = isPrintCost;
    }
    @Override
    public String rendering() {