input: Write a function to sort a dictionary according to its values in descending order. If the dictionary is empty, return the empty dictionary.
  sorted_dictionary = sortDictionary({'apple': 2, 'banana': 3, 'mango': 1})
  assert sorted_dictionary == {'banana': 3, 'apple': 2, 'mango': 1}
  sorted_dictionary = sortDictionary({})
  assert sorted_dictionary == {}
output: def sortDictionary(d):
      return {k: v for k, v in sorted(d.items(), key=lambda item: item[1], reverse=True)}