constructor() {
		/** @type {Map<K, V>} */
		this.map = new Map();
		/** @type {ReadonlyMap<K, V>[]} */
		this.stack = [];
	}
The StackedCacheMap is a data structure designed as an alternative to a Map
in situations where you need to handle multiple item additions and
frequently access the largest map.

It is particularly optimized for efficiently adding multiple items
at once, which can be achieved using the `addAll` method.

It has a fallback Map that is used when the map to be added is mutable.

Note: `delete` and `has` are not supported for performance reasons.
@example
```js
const map = new StackedCacheMap();
map.addAll(new Map([["a", 1], ["b", 2]]), true);
map.addAll(new Map([["c", 3], ["d", 4]]), true);
map.get("a"); // 1
map.get("d"); // 4
for (const [key, value] of map) {
		console.log(key, value);
}
```
@template K
@template V