ArrayListCombiner.java

package ArrayListCombiner;

import java.util.ArrayList;

/**
 * Create two generic methods that take two arraylists.  The methods should both append the second ArrayList's items,
 * to the first.  Use a wildcard for one of the type arguments in each method.
 * The first method should be called extendCombiner and should use ? extends E
 * The second method should be called superCombiner and should use ? super E
 */
public class ArrayListCombiner<E> {

//    private ArrayList<E> first;
//    private ArrayList<E> second;

    public ArrayListCombiner() {
//        first = new ArrayList<>();
//        second = new ArrayList<>();
    }

    public static <E> void extendCombiner(ArrayList<E> first, ArrayList<? extends E> second) {
        first.addAll(second);

    }

    public static <E> void superCombiner(ArrayList<? super E> first, ArrayList<E> second) {
        first.addAll(second);

    }

}