PriorityQueue<aeronaves> pil= new PriorityQueue();
 pil.offer(new aeronaves("avianca",500));
 pil.offer(new aeronaves("linux",400));
 pil.offer(new aeronaves("avianca",500));
 pil.offer(new aeronaves("tame",2000));
 pil.offer(new aeronaves("tame",500));
 pil.offer(new aeronaves("arca",200));
 while(!pil.isEmpty()){
      aeronaves ae= pil.poll();
      System.out.println("aerolina saliento: "+ae.getAerolinea()+"destino "+ae.getDestino());
 }


@Override
public int compareTo(aeronaves t) {
    if(t.getDestino<500){
        return -1;
 }
if(t.getDestino>=500|| t.getDestino<1000){
        return 0;
}else{
        return 1;
 }
}