// import ALL useful classes
import java.util.*;
class lamp {
  
  int static count = 0;
      public int id;
  public static List<lamp> Lamps = new ArrayList<lamp>();
  
  public lamp() {
    if (Lamps.size() >= 10) {
      throw new NullPointerException("It is impossible to have more than 10 lamps!");
    }
    // give every instance an unique id
    this.id = count++;
    Lamps.add(this);
  }
  
  public List<lamp> getLamps() {
    // ensure user cannot change this list
    return Collections.unmodifiableList(Lamps);
  }
  
  public static void main(String[] args) {
    while (true) {
      lamp m = new lamp();
      System.out.println(m.id);
    }}}

Mille vastu on koodi kirjutamisel eksitud (vali 5)?