input: Write a function to sort a given list of items in descending order in Python. If the list is empty, return it as it is.
  assert sort_descending([3, 7, 5, 8, 10])==[10, 8, 7, 5, 3]
  assert sort_descending([9, 2, 6, 1, 4, 5])==[9, 6, 5, 4, 2, 1]
  assert sort_descending([1, 2, 3, 4, 5])==[5, 4, 3, 2, 1]
  assert sort_descending([])==[]
output: def sort_descending(lst):
      return sorted(lst, reverse=True)