public class MiObjeto extends Object {
   private int x;
   public MiObjeto(int x0) {
      super();
      x=x0;
   }
   public String toString() {
      return "x="+this.x;
   }
   public boolean equals(Object obj){
      if (obj instanceof MiObjeto) {
        MiObjeto otro= (MiObjeto) obj;
        return this.x == otro.x;
      }
      return false;
   } 
  // public Class getClass() { return null;}
}