public class PairVar<S> implements Pair<S> {

    private S first;
    private S second;

    public PairVar(S first, S second) {
       this.first = first;
       this.second = second;
   }

   public S getFirst() {
       return this.first;
   }

   public S getSecond() {
       return this.second;
   }

   public void setFirst(S value) {
       this.first = value;
   }

   public void setSecond(S value) {
       this.second = value;
   }

}