input: Write a function to shuffle a given list. If the given list is empty, the function should return an empty list.
  assert shuffle_list([1, 2, 3, 4, 5]) is not None
  assert shuffle_list([]) == []
output: import random
  
  def shuffle_list(lst):
      if not lst:
          return []
      shuffled = lst[:]
      random.shuffle(shuffled)
      return shuffled