input: Write a python function to sort an array using the provided function.
  assert sort_array([3, 6, 8, 10, 1, 2, 1]) == [1, 1, 2, 3, 6, 8, 10]
  assert sort_array([10, 9, 8, 7, 6, 5, 4, 3, 2, 1]) == [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
  assert sort_array([]) == []
  assert sort_array([5]) == [5]
  assert sort_array([4, 4, 4, 4, 4]) == [4, 4, 4, 4, 4]
output: def sort_array(arr):
      return sorted(arr)