Observations

public class N extends AbstractSet<Integer> {
  public Iterator iterator() {
    return new Iterator() {
      int n = 0;
      public boolean hasNext() {
        return true;
      }

      public Integer next() {
        return n++;
      }

      public void remove() {
        throw new UnsupportedOperationException();
      }
    };
  }

  public int size() {
    return Integer.MAX_VALUE;
  }
}