code: def _get_groups(self, data):
          
          groups = []
          for attribute in SOURCE_KEYS:
              for k, v in data[attribute].items():
                  if k == None:
                      k = 'Sources'
                  if k not in groups:
                      groups.append(k)
          for k, v in data['include_files'].items():
              if k == None:
                  k = 'Includes'
              if k not in groups:
                  groups.append(k)
          return groups
docs: Get all groups defined