input: Write a function to sort the list items in descending order. If the input list is empty, return an empty list. Otherwise, return the sorted list in descending order.
  assert sort_descending([3, 7, 5, 8, 10])==[10, 8, 7, 5, 3]
  assert sort_descending([5, 3, 7, 1])==[7, 5, 3, 1]
  assert sort_descending([])==[]
output: def sort_descending(lst):
      return sorted(lst, reverse=True)