>>> hashNub [3, 3, 3, 2, 2, -1, 1] [3,2,-1,1]
>>> intNub [3, 3, 3, 2, 2, -1, 1] [3,2,-1,1]
>>> intNubOn fromEnum "ababbbcdaffee" "abcdfe"
>>> ordNub [3, 3, 3, 2, 2, -1, 1] [3,2,-1,1]
>>> ordNubOn (`div` 10) [3, 3, 3, 13, 2, 22, -1, 1, 66] [3,13,22,-1,66]
>>> sortNub [3, 3, 3, 2, 2, -1, 1] [-1,1,2,3]
>>> unstableNub [3, 3, 3, 2, 2, -1, 1] [1,2,3,-1]