docs: def each_do(action: Callable[[T], None]):
      """
      >>> from Redy.Collections import Traversal, Flow
      >>> lst: Iterable[int] = [1, 2, 3]
      >>> def action(x: int) -> None: print(x)
      >>> x = Flow(lst)[Traversal.each_do(action)]
      >>> assert x.unbox is None
      """
  
      def inner(collection: ActualIterable[T]):
          for each in collection:
              action(each)
  
      return inner