input: Write a function to sort and print out the elements of an array of integers. If the array is empty, print an empty list. The function should return None.
  assert sort_and_print([17, 41, 5, 22, 54, 6, 29, 3, 13])==None
  assert sort_and_print([])==None
output: def sort_and_print(arr):
      print(sorted(arr))
      return None