message: docs: restore UniqueAlterEgoValidator
  Update the docregion for the directive class to differentiate them
  PR Close
diff: @@ -10,6 +10,21 @@ import { HeroesService } from './heroes.service';
  import { Observable, of } from 'rxjs';
  // #docregion async-validator
  +@Injectable({ providedIn: 'root' })
  +export class UniqueAlterEgoValidator implements AsyncValidator {
  + constructor(private heroesService: HeroesService) {}
  +
  + validate(
  + control: AbstractControl
  + ): Observable<ValidationErrors | null> {
  + return this.heroesService.isAlterEgoTaken(control.value).pipe(
  + map(isTaken => (isTaken ? { uniqueAlterEgo: true } : null)),
  + catchError(() => of(null))
  + );
  + }
  +}
  +// #enddocregion async-validator
  +
  // #docregion async-validator-directive
  @Directive({
  selector: '[appUniqueAlterEgo]',
  @@ -21,7 +36,6 @@ import { Observable, of } from 'rxjs';
  }
  ]
  })
  -// #enddocregion async-validator-directive
  export class UniqueAlterEgoValidatorDirective implements AsyncValidator {
  constructor(private heroesService: HeroesService) {}
  @@ -34,4 +48,4 @@ export class UniqueAlterEgoValidatorDirective implements AsyncValidator {
  );
  }
  }
  -// #enddocregion async-validator
  +// #enddocregion async-validator-directive
  