docs: def chunk(seq: ActualIterable[T]) -> ActualIterable[ActualIterable[T]]:
      """
      >>> from Redy.Collections import Traversal, Flow
      >>> x = [1, 1, 2]
      >>> assert Flow(x)[Traversal.chunk][list].unbox == [[1, 1], [2]]
      >>> assert Flow([])[Traversal.chunk][list].unbox == []
      """
      seq = iter(seq)
      try:
          head = next(seq)
      except StopIteration:
          return iter(seq)
  
      current_status = head
      group = [head]
      for each in seq:
          status = each
          if status != current_status:
              yield group
              group = [each]
          else:
              group.append(each)
          current_status = status
      if group:
          yield group