input: Write a python function to sort an array.
  assert sort_array([5, 3, 8, 6, 2]) == [2, 3, 5, 6, 8]
  assert sort_array([10, 20, 5, 3, 15]) == [3, 5, 10, 15, 20]
  assert sort_array([1, 4, 3, 2, 5]) == [1, 2, 3, 4, 5]
output: def sort_array(arr):
      return sorted(arr)