SortedSet interface methods in java

The SortedSet interface is used by TreeSet and adds additional methods to reflect that a TreeSet is sorted.

SortedSet sset;

Result	Method	Description
comp =	sset.comparator()	Returns Comparator used to compare elements. null if natural ordering used (eg, String).
obj =	sset.firstKey()	First element (in sorted order).
obj =	sset.lastKey()	Last element (in sorted order).
sset =	sset.headMap(obj)	Returns SortedSet of all elements less than obj.
sset =	sset.tailMap(obj)	Returns SortedSet of all elements greater than or equal to obj.
sset =	sset.subMap(from, to)	Returns SortedSet of all elements greater than or equal to from and less than to.