code: def unchanged(self):
          '''
          Returns all keys that have been unchanged.
  
          If the keys are in child dictionaries they will be represented with
          . notation
          '''
          def _unchanged(current_dict, diffs, prefix):
              keys = []
              for key in current_dict.keys():
                  if key not in diffs:
                      keys.append('{0}{1}'.format(prefix, key))
                  elif isinstance(current_dict[key], dict):
                      if 'new' in diffs[key]:
                          # There is a diff
                          continue
                      else:
                          keys.extend(
                              _unchanged(current_dict[key],
                                         diffs[key],
                                         prefix='{0}{1}.'.format(prefix, key)))
  
              return keys
          return sorted(_unchanged(self.current_dict, self._diffs, prefix='')f unchanged(self):
          '''
          Returns all keys that have been unchanged.
  
          If the keys are in child dictionaries they will be represented with
          . notation
          '''
          def _unchanged(current_dict, diffs, prefix):
              keys = []
              for key in current_dict.keys():
                  if key not in diffs:
                      keys.append('{0}{1}'.format(prefix, key))
                  elif isinstance(current_dict[key], dict):
                      if 'new' in diffs[key]:
                          # There is a diff
                          continue
                      else:
                          keys.extend(
                              _unchanged(current_dict[key],
                                         diffs[key],
                                         prefix='{0}{1}.'.format(prefix, key)))
  
              return keys
          return sorted(_unchanged(self.current_dict, self._diffs, prefix=''))
docs: Returns all keys that have been unchanged.
  
          If the keys are in child dictionaries they will be represented with
          . notation