code: func SubredditComments(
  	scanner reddit.Scanner,
  	kill <-chan bool,
  	errs chan<- error,
  	subreddits ...string,
  ) (
  	<-chan *reddit.Comment,
  	error,
  ) {
  	path := "/r/" + strings.Join(subreddits, "+") + "/comments"
  	_, comments, _, err := streamFromPath(scanner, kill, errs, path)
  	return comments, err
  }
docs: // SubredditComments returns a stream of new comments 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 comments are new, and will not have reply trees. If you
  // are interested in comment trees, save the permalinks of their parent posts
  // and fetch them later once they may have had activity.