/*
* 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);
}
