/* * Adds the specified object to this {@code TreeSet}. * * @param object * the object to add. * @return {@code true} when this {@code TreeSet} did not already contain * the object, {@code false} otherwise. * @throws ClassCastException * when the object cannot be compared with the elements in this * {@code TreeSet}. * @throws NullPointerException * when the object is null and the comparator cannot handle * null. */ public override bool add(E obj) { return(backingMap.put(obj, java.lang.Boolean.TRUE) == null); }