new CollectionTransformer

gistfile1.java

public class CollectionTransformer<E> implements UnaryFunction<Generator<? extends E>, Collection<? super E>> {

    // instance methods
    //---------------------------------------------------
    /**
     * {@inheritDoc}
     */
    public Collection<? super E> evaluate(Generator<? extends E> generator) {
        final List<? super E> list = new ArrayList<E>();
        generator.run(new UnaryProcedure<E>() {
            public void run(E obj) {
                list.add(obj);
            }
        });
        return list;
    }

    /**
     * Get a {@link CollectionTransformer} instance that simply returns any {@link Collection}.
     * @return {@link CollectionTransformer}
     */
    public static <E> CollectionTransformer<E> toCollection() {
        return new CollectionTransformer<E>();
    }
}