Functional Java

package swensen.functional;

/**
 * A Tuple2 implementation representing a grouping by key
 * @param <E> the element type
 */
public class Grouping<R,E> extends Tuple2<R,Seq<E>> {
    public Grouping(R key, Seq<E> grouping) {
        super(key, grouping);
    }

    /**
     * Create a Grouping tuple from the given key (t1) and grouping (t2).
     * @param key the grouping key
     * @param grouping the grouping
     * @param <R> the key type
     * @param <E> the grouping type
     * @return a new Grouping
     */
    public static <R,E> Grouping<R,E> create(R key, Seq<E> grouping) {
        return new Grouping(key,grouping);
    }

    /**
     * A helper naming this.t1 as "key"
     * @return this.t1
     */
    public R getKey() {
        return t1;
    }

    /**
     * A helper naming this.t2 as "grouping"
     * @return this.t2
     */
    public Seq<E> getGrouping() {
        return t2;
    }
}