Method asSet

lib/util/StackedMap.js:168–171

* Returns the visible keys as a `Set` after collapsing the stack. * @returns {Set<K>} set of keys

()

	 * @returns {Set<K>} set of keys
	 */
	asSet() {
		this._compress();
		return new Set(this.map.keys());
	}

	/**
	 * Returns visible key/value pairs using the external representation.