Method add

lib/util/LazySet.js:120–123

* Adds a single item immediately to the concrete backing set. * @param {T} item an item * @returns {LazySet<T>} itself

(item)

	 * @returns {LazySet<T>} itself
	 */
	add(item) {
		this._set.add(item);
		return this;
	}

	/**
	 * Queues another iterable or lazy set for later merging so large bulk adds