text: public static CharArraySet UnmodifiableSet(CharArraySet set){if (set == null){throw new System.ArgumentNullException("Given set is null");}if (set == EMPTY_SET){return EMPTY_SET;}if (set.map is CharArrayMap.UnmodifiableCharArrayMap<object>){return set;}return new CharArraySet(CharArrayMap.UnmodifiableMap<object>(set.map));}