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

    private S[] elems;

    @SuppressWarnings("unchecked")
    
    public PairArray(S first, S second) {
       elems = (S[]) new Object[2];
       elems[0] = first;
       elems[1] = second;
   }

   public S getFirst() {
       return elems[0];
   }

   public S getSecond() {
       return elems[1];
   }

   public void setFirst(S value) {
       elems[0] = value;
   }

   public void setSecond(S value) {
       elems[1]= value;
   }

}