input: Write a python function to generate a random permutation of a list.
  assert sorted(randomize([1, 2, 3, 4, 5]))==[1, 2, 3, 4, 5]
  assert sorted(randomize([10, 20, 30, 40, 50]))==[10, 20, 30, 40, 50]
  assert sorted(randomize([5, 15, 25, 35, 45]))==[5, 15, 25, 35, 45]
output: import random
  
  def randomize(lst):
      lst_copy = lst[:]
      random.shuffle(lst_copy)
      return lst_copy