4. (25pts) Design and implement an accumulator style Racket function which consumes a SORTED list of number as its parameters and produces a list of number. It removes consecutive duplicates from a list. (check-expect funtion-name (list 1 2 2 3 4 5 5)) (list 5 4 3 2 1)) (check-expect (funtion-name (list 1 1 1 1)) (list 1)) (check-expect funtion-name (list 1 2 3 4)) (list 4 3 2 1)) (check-expect funtion-name (list 1 2 2 2 2 3 3 3 3 4 5 6 6 6 )) (list 6 5 4 3 2 1))