public void addNode(int value, int leftValue, int rightValue) {
            if (leftValue == -1 && rightValue == -1) {
                return;
            }

            Node node = this.getNodeByValue(value);
            if (node == null) {
                System.out.println("Error, no node with value:" + value);
                return;
            }

            if (leftValue != -1) {
                node.leftChild = new Node(leftValue, node);
            }
            if (rightValue != -1) {
                node.rightChild = new Node(rightValue, node);
            }
        }