input: Write a function to shuffle a list of numbers. The function should return a shuffled version of the input list.
  import random
  
  def shuffle_list(nums):
   random.shuffle(nums)
   return nums
  
  assert shuffle_list([1, 2, 3, 4, 5]) != [1, 2, 3, 4, 5]
  assert len(shuffle_list([1, 2, 3, 4, 5])) == 5
  assert shuffle_list([]) == []
output: import random
  
  def shuffle_list(nums):
      shuffled = nums[:]
      random.shuffle(shuffled)
      return shuffled