Binary search tree Node class in Java

As a supportive thing for some careercup challenges I wrote a class for a BST Node.

    public class Node {
        Node left;
        Node right;
        Node parent;
        int data;
        Node(int data, Node parent) {
            this.data = data;
            this.parent = parent;
        }
        /**
         * Put an int into left node and return it
         * @return Node
         */
        protected Node putLeft(int data) {
            if (this.left == null) {
                this.left = new Node(data, this);
                return this.left;
            } else {
                return left.put(data);
            }
        }
        /**
         * Put an int into right node and return it
         * @return Node
         */
        protected Node putRight(int data) {
            if (this.right == null) {
                this.right = new Node(data, this);
                return this.right;
            } else {
                return right.put(data);
            }

        }
        /**
         * Ask Node to put an int into its children and return it
         * @return Node
         */
        public Node put(int data) {
            if (data == this.data) {
                return this;
            } else {
                return data < this.data ? this.putLeft(data) : this.putRight(data);
            }
        }
        @Override
        public String toString() {
            // Example: 20 {10, 30}
            String l = this.left != null ? String.valueOf(left.data) : "";
            String r = this.right != null ? String.valueOf(right.data) : "";
            String c = "";
            if (this.left != null || this.right != null) {
                c = " {"+ l +", " + r +"}";
            }
            return String.valueOf(this.data) + c;
        }
    }

It also stores the reference to the parent Node so you can traverse the tree once you have the Node object

Usage:

Node root = new Node(20, null);
root.put(10);
root.put(30);
root.put(5);
System.out.println(root); // 20 {10, 30}
System.out.println(root.left); // 10 {5, }
System.out.println(root.right.parent); // 20 {10, 30}

I didn’t add getters here to make the code shorter (KISS)