input: Write a function in Python to sort a dictionary according to its values, in descending order.
  
  ### Input:
  dictionary = {'apple': 2, 'banana': 3, 'mango': 1}
  
  ### Output:
  def sortDictionary(dictionary):
    sorted_list = sorted(dictionary.items(), key=lambda x: x[1], reverse=True)
    sorted_dictionary = dict(sorted_list)
    return sorted_dictionary
  
  assert sortDictionary({'apple': 2, 'banana': 3, 'mango': 1})=={'banana': 3, 'apple': 2, 'mango': 1}
  assert sortDictionary({'car': 5, 'bus': 4, 'train': 7})=={'train': 7, 'car': 5, 'bus': 4}
  assert sortDictionary({'a': 1, 'b': 2, 'c': 3})=={'c': 3, 'b': 2, 'a': 1}
  assert sortDictionary({})=={}
output: def sortDictionary(dictionary):
    sorted_list = sorted(dictionary.items(), key=lambda x: x[1], reverse=True)
    sorted_dictionary = dict(sorted_list)
    return sorted_dictionary