Method union

src/main/java/groovy/util/GroovyCollections.java:266–268

Returns an ordered set of all the unique items found in the provided argument iterables. assert GroovyCollections.union([1, 2], [2, 3], [1, 4]) == [1, 2, 3, 4] @param iterables the sources of items @return the ordered list of unique values found @

(Iterable<T>... iterables)

     * @since 4.0.0
     */
    public static <T> List<T> union(Iterable<T>... iterables) {
        return union(Arrays.asList(iterables));
    }

    /**
     * Returns an ordered set of all the unique items found in the provided argument iterables.