Subtree of Another Tree

# Introduction

In this challenge, we will be working with binary trees. The task is to determine if a given tree contains a subtree with the same structure and node values as another given tree. We need to implement a function called `isSubtree` that takes in two parameters, `root` and `subRoot`, which represent the root nodes of the trees. The function should return `true` if `root` contains a subtree that matches `subRoot`, and `false` otherwise.