@Override public PersistentVector<E> concat(Iterable<? extends E> items) {
        return (PersistentVector<E>) ImList.super.concat(items);
    }
@Override public PersistentVector<E> concat(Iterable<? extends E> items) {
        return (PersistentVector<E>) ImList.super.concat(items);
    }
@ Override public PersistentVector < E > concat ( Iterable < ? extends E > items ) { return ( PersistentVector < E > ) ImList . super . concat ( items ) ; }
Efficiently adds items to the end of this PersistentVector.
@param items the values to insert
@return a new PersistentVector with the additional items at the end.
Efficiently adds items to the end of this PersistentVector .