class CompactHashSet extends java.util.AbstractSet<E> {

  @Override
  public boolean contains(Object o) {
    if (o == null) o = nullObject;
    
    int hash = o.hashCode();
    int index = (hash & 0x7FFFFFFF) % objects.length;
    int offset = 1;

    // search for the object (continue while !null and !this object)
    while(objects[index] != null &&
          !(objects[index].hashCode() == hash &&
            objects[index].equals(o))) {
      index = ((index + offset) & 0x7FFFFFFF) % objects.length;
      offset = offset*2 + 1;

      if (offset == -1)
        offset = 2;
    }

    return objects[index] != null;
  }

  public  CompactHashSet();
  public  CompactHashSet(int size);
  public  CompactHashSet(Collection<E> c);

}