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