throw new Error ("FIXME: compiler error - AbstractSet.equals");
return containsAll((Collection)o);
  public boolean equals(Object o) {    if (o == this) {      return true;    } else if (o instanceof Set && ((Set)o).size() == size()) {      throw new Error ("FIXME: compiler error - AbstractSet.equals");      /*  FIXME: this is the correct implementation, but a compiler	  error prevents us from building it.	  return containsAll((Collection)o);  */    } else {      return false;    }  }