input: Write a function to shuffle an array of integers using the `random.shuffle` function from the `random` module. The function should return the shuffled array.
  
  def shuffle(arr):
      random.shuffle(arr)
      return arr 
  
  assert shuffle([1, 5, 9, 4, 2]) != [1, 5, 9, 4, 2]
  assert sorted(shuffle([1, 5, 9, 4, 2])) == [1, 2, 4, 5, 9]
  assert isinstance(shuffle([1, 5, 9, 4, 2]), list)
  assert len(shuffle([1, 5, 9, 4, 2])) == 5
output: def shuffle(arr):
      random.shuffle(arr)
      return arr