code: func Reverse() Filter {
  	return FilterFunc(func(arg Arg) error {
  		var data []string
  		for s := range arg.In {
  			data = append(data, s)
  		}
  		for i := len(data) - 1; i >= 0; i-- {
  			arg.Out <- data[i]
  		}
  		return nil
  	})
  }
docs: // Reverse yields items in the reverse of the order it received them.