var assert = require('assert');

​

function TreeNode(val) {

    this.val = val

    this.left = null

    this.right = null

}

​

/**

 * @param {TreeNode} root

 * @param {number} low

 * @param {number} high

 * @return {number}

 */

function sumRangeBST(root, low, high) {

    return

}

​

try {

    let root = new TreeNode(10)

    root.left = new TreeNode(5)

    root.right = new TreeNode(15)

    root.left.left = new TreeNode(3)

    root.left.right = new TreeNode(7)

    root.right.right = new TreeNode(18)

    assert.equal(sumRangeBST(root, 7, 15), 32);

​