input: Write a python function to sort an array.
  assert sort_array([3, 5, 9, 11, 1, 4]) == [1, 3, 4, 5, 9, 11]
  assert sort_array([10, 7, 3, 8, 5, 2]) == [2, 3, 5, 7, 8, 10]
  assert sort_array([15, 12, 14, 10, 8, 7]) == [7, 8, 10, 12, 14, 15]
output: def sort_array(arr):
      return sorted(arr)