has(...args) {
		let map = this._map;
		for (let i = 0; i < args.length - 2; i++) {
			const arg = args[i];
			map = /** @type {InnerMap<T, V>} */ (map.get(arg));
			if (map === undefined) {
				return false;
			}
		}

		const beforeLast = args[args.length - 2];
		const set = map.get(beforeLast);
		if (set === undefined) {
			return false;
		}

		const last = args[args.length - 1];
		return set.has(last);
	}
@param {[T, V, ...EXPECTED_ANY]} args tuple
@returns {boolean} true, if the tuple is in the Set