// `text` has type `string`
window.alert = (text) => {
	return window.alert(text);
}

// Both parameters are `any`, because `addEventListener` has overloads
window.addEventListener = (type, fn) => {
	return window.addEventListener(type, fn);
}

addEventListener<K extends keyof WindowEventMap>(type: K, listener: (this: Window, ev: WindowEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;