fun TreeSet(c: Comparator?) { this(TreeMap(c)) }
Constructs a new , empty set , sorted according to the specified comparator . All elements inserted into the set must be < i > mutually comparable < /i > by the specified comparator : < tt > comparator.compare ( e1 , e2 ) < /tt > must not throw a < tt > ClassCastException < /tt > for any elements < tt > e1 < /tt > and < tt > e2 < /tt > in the set . If the user attempts to add an element to the set that violates this constraint , the < tt > add ( Object ) < /tt > call will throw a < tt > ClassCastException < /tt > .