@Override
 public int hashCode() {
   final int prime = 31;
   int result = 1;
   result = prime * result + ((aduana == null) ? 0 : aduana.hashCode());
   result = prime * result + ((operador == null) ? 0 : operador.hashCode());
   return result;
 }
 @Override
 public boolean equals(Object obj) {
   if (this == obj) return true;
   if (obj == null) return false;
   if (getClass() != obj.getClass()) return false;
   OperadorPorAduana other = (OperadorPorAduana) obj;
   if (aduana == null) {
     if (other.aduana != null) return false;
   } else if (!aduana.equals(other.aduana)) return false;
   if (operador == null) {
     if (other.operador != null) return false;
   } else if (!operador.equals(other.operador)) return false;
   return true;
 }