source: src/main/java/agents/anac/y2011/IAMhaggler2011/Pair.java

package agents.anac.y2011.IAMhaggler2011;
import java.io.Serializable;

public class Pair<A, B> implements Serializable {

        private static final long serialVersionUID = -3160841691791187933L;
        public final A fst;
        public final B snd;

        /**
         * @param fst
         *            First value.
         * @param snd
         *            Second value.
         */
        public Pair(A fst, B snd) {
                this.fst = fst;
                this.snd = snd;
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Object#toString()
         */
        public String toString() {
                return "Pair[" + fst + "," + snd + "]";
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Object#equals(java.lang.Object)
         */
        public boolean equals(Object other) {
                return other instanceof Pair<?, ?> && equals(fst, ((Pair<?, ?>) other).fst) && equals(snd, ((Pair<?, ?>) other).snd);
        }

        private static boolean equals(Object x, Object y) {
                return (x == null && y == null) || (x != null && x.equals(y));
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Object#hashCode()
         */
        public int hashCode() {
                if (fst == null)
                        return (snd == null) ? 0 : snd.hashCode() + 1;
                else if (snd == null)
                        return fst.hashCode() + 2;
                else
                        return fst.hashCode() * 17 + snd.hashCode();
        }

        public static <A, B> Pair<A, B> of(A a, B b) {
                return new Pair<A, B>(a, b);
        }
}