isSubtree = function (root, subRoot) {
    if (!root) return false

    if (isSame(root, subRoot)) return true

    const hasLeftTree = isSubtree(root.left, subRoot)
    const hasRightTree = isSubtree(root.right, subRoot)

    return hasLeftTree || hasRightTree
}
https://leetcode.com/problems/subtree-of-another-tree/
@param {TreeNode} root
@param {TreeNode} subRoot
@return {boolean}