If a route load is cancelled (for example, by clicking two links rapidly in succession), `routeChangeError` will fire. And the passed `err` will contain a `cancelled` property set to `true`, as in the following example:
Router events should be registered when a component mounts ([useEffect](https://reactjs.org/docs/hooks-effect.html) or [componentDidMount](https://reactjs.org/docs/react-component.html#componentdidmount) / [componentWillUnmount](https://reactjs.org/docs/react-component.html#componentwillunmount)) or imperatively when an event happens, as in the following example: