reverseOrder
Returns a comparator that imposes the reverse ordering of the specified comparator. If the specified comparator is null, this method is equivalent to .reverseOrder (in other words, it returns a comparator that imposes the reverse of the natural ordering on a collection of objects that implement the Comparable interface).
The returned comparator is serializable (assuming the specified comparator is also serializable or null).
Return
A comparator that imposes the reverse ordering of the specified comparator.
Since
1.5
Parameters
cmp
a comparator who's ordering is to be reversed by the returned comparator or null