message: docs(aio): unified string chaining
  PR Close
diff: @@ -123,6 +123,6 @@ export class HeroService {
  /** Log a HeroService message with the MessageService */
  private log(message: string) {
  - this.messageService.add('HeroService: ' + message);
  + this.messageService.add(`HeroService: ${message}`);
  }
  }
  