code: def group(seq: ActualIterable[T]) -> Dict[TR, List[T]]:
      
      ret = defaultdict(list)
      for each in seq:
          ret[each].append(each)
      return ret
docs: >>> from Redy.Collections import Flow, Traversal
      >>> x = [1, 1, 2]
      >>> Flow(x)[Traversal.group].unbox