Method union

src/lualib/Set.ts:170–176

* @returns a new Set containing all the elements in this Set and also all the elements in the argument.

(other: ReadonlySet<T>)

     * @returns a new Set containing all the elements in this Set and also all the elements in the argument.
     */
    public union(other: ReadonlySet<T>): Set<T> {
        const result = new Set<T>(this);
        for (const item of other) {
            result.add(item);
        }
        return result;
    }

    /**
     * @returns a new Set containing all the elements which are both in this Set and in the argument.