Creating a Small Helper Class to Safely Handle CancellationTokenSource Cancel and Dispose

Introduction

When writing async code in Unity, you often end up working with CancellationToken for loading, networking, Addressables, screen transitions, timeouts, and so on.

The object you usually create for that is CancellationTokenSource, but it is surprisingly easy to handle it incorrectly.

For example:

private CancellationTokenSource? _cts;