code: def old_values(self):
          '''Returns the old values from the diff'''
          def get_old_values_and_key(item):
              values = item.old_values
              values.update({self._key: item.past_dict[self._key]})
              return values
  
          return [get_old_values_and_key(el)
                  for el in self._get_recursive_difference('all')
                  if el.diffs and el.past_dictf old_values(self):
          '''Returns the old values from the diff'''
          def get_old_values_and_key(item):
              values = item.old_values
              values.update({self._key: item.past_dict[self._key]})
              return values
  
          return [get_old_values_and_key(el)
                  for el in self._get_recursive_difference('all')
                  if el.diffs and el.past_dict]
docs: Returns the old values from the diff