input: Write a python function to sort a list of integers in descending order.
  assert sorted_descending([5, 2, 9, 1, 5, 6])==[9, 6, 5, 5, 2, 1]
  assert sorted_descending([3, 0, -1, 8, 7, 2])==[8, 7, 3, 2, 0, -1]
  assert sorted_descending([1, 2, 3, 4, 5])==[5, 4, 3, 2, 1]
output: def sorted_descending(lst):
      return sorted(lst, reverse=True)