input: Write a python function to shuffle an array.
  assert sorted(shuffle_array([1, 2, 3, 4, 5]))==[1, 2, 3, 4, 5]
  assert sorted(shuffle_array([10, 20, 30, 40, 50]))==[10, 20, 30, 40, 50]
  assert sorted(shuffle_array([100, 200, 300, 400, 500]))==[100, 200, 300, 400, 500]
output: import random
  
  def shuffle_array(arr):
      random.shuffle(arr)
      return arr