code: func Subreddits(
  	scanner reddit.Scanner,
  	kill <-chan bool,
  	errs chan<- error,
  	subreddits ...string,
  ) (
  	<-chan *reddit.Post,
  	error,
  ) {
  	path := "/r/" + strings.Join(subreddits, "+") + "/new"
  	posts, _, _, err := streamFromPath(scanner, kill, errs, path)
  	return posts, err
  }
docs: // Subreddits returns a stream of new posts from the requested subreddits. This
  // stream monitors the combination listing of all subreddits using Reddit's "+"
  // feature e.g. /r/golang+rust. This will consume one interval of the handle per
  // call, so it is best to gather all the subreddits needed and invoke this
  // function once.
  //
  // Be aware that these posts are new and will not have comments. If you are
  // interested in comment trees, save their permalinks and fetch them later.