docs: def issue_mode_to_enum(deck: DeckSpawnProto, issue_mode: list) -> int:
      '''encode issue mode(s) as bitfeg'''
  
      # case where there are multiple issue modes specified
      if isinstance(issue_mode, list) and len(issue_mode) > 1:
          r = 0
          for mode in issue_mode:
              r += deck.MODE.Value(mode)
          return r
  
      elif isinstance(issue_mode, str):  # if single issue mode
          return deck.MODE.Value(issue_mode)
  
      else:
          raise InvalidDeckIssueMode({'error': 'issue_mode given in wrong format.'})