docs: def flatten_reducer(
          flattened_list: list,
          entry: typing.Union[list, tuple, COMPONENT]
  ) -> list:
      """
      Flattens a list of COMPONENT instances to remove any lists or tuples
      of COMPONENTS contained within the list
  
      :param flattened_list:
          The existing flattened list that has been populated from previous
          calls of this reducer function
      :param entry:
          An entry to be reduced. Either a COMPONENT instance or a list/tuple
          of COMPONENT instances
      :return:
          The flattened list with the entry flatly added to it
      """
  
      if hasattr(entry, 'includes') and hasattr(entry, 'files'):
          flattened_list.append(entry)
      elif entry:
          flattened_list.extend(entry)
      return flattened_list