code: def _iterate(self, data, expanded_data):
          
          for attribute in SOURCE_KEYS:
              for k, v in data[attribute].items():
                  if k == None:
                      group = 'Sources'
                  else:
                      group = k
                  if group in data[attribute].keys():
                      self._expand_data(data[attribute][group], expanded_data, group)
          for k, v in data['include_files'].items():
              if k == None:
                  group = 'Includes'
              else:
                  group = k
              self._expand_data(data['include_files'][group], expanded_data, group)
  
          # sort groups
          expanded_data['groups'] = OrderedDict(sorted(expanded_data['groups'].items(), key=lambda t: t[0]))
docs: _Iterate through all data, store the result expansion in extended dictionary