input: Write a python function to sort a list of integers in descending order.
  assert sort_descending([1, 5, 3, 2, 4]) == [5, 4, 3, 2, 1]
  assert sort_descending([10, 20, 5, 15, 25]) == [25, 20, 15, 10, 5]
  assert sort_descending([3, 3, 3, 3, 3]) == [3, 3, 3, 3, 3]
  assert sort_descending([]) == []
output: def sort_descending(lst):
      return sorted(lst, reverse=True)