input: Write a function to sort the given list in descending order. The function should directly modify the input list without returning a new list.
  list_items = [3, 7, 5, 8, 10]
  assert sort_descending(list_items) == None
  assert list_items == [10, 8, 7, 5, 3]
  
  list_items = [20, 15, 18, 25, 12]
  assert sort_descending(list_items) == None
  assert list_items == [25, 20, 18, 15, 12]
  
  list_items = []
  assert sort_descending(list_items) == None
  assert list_items == []
output: def sort_descending(list_items):
      list_items.sort(reverse=True)