message: docs: add missing type when handling errors in hero service.
  PR Close
diff: @@ -42,7 +42,7 @@ export class HeroService {
  // #enddocregion getHeroes-2
  tap(_ => this.log('fetched heroes')),
  // #docregion getHeroes-2
  - catchError(this.handleError('getHeroes', []))
  + catchError(this.handleError<Hero[]>('getHeroes', []))
  );
  // #docregion getHeroes-1
  }
  