多次调用SharedModule服务构造函数

我在用角度 Core/Feature/Shared 模块模式。

什么时候? CoreComponent (应用程序的主页)呈现时 DataStorageService 的构造函数(用于 核心成分 的构造函数)被多次调用(每次调用构造函数时都会导致AJAX调用)

请不要将我的问题标记为重复问题,因为我的问题与以前在这里提出和回答的类似问题有点不同。
我附上了我的代码来说明我的意思(为了简单起见,我把它缩短了)。

核心/共享模块.ts

@NgModule({
  declarations: [...],
  imports: [...],
  exports: [... ],
})
export class SharedModule {

  static forRoot(): ModuleWithProviders {
    return {
      ngModule: SharedModule,
      providers: [XHRService, DataStorageService]
    };
  }
}

共享/服务/数据存储.service.ts

@Injectable()
export class DataStorageService {
  constructor(private xhr: XHRService) {
    this.loadEvents()
  }

  public loadOrigination = () => this.xhr.getOriginationsList().subscribe(this.originationsSource);
  public loadEvents = () => this.xhr.getEventsList().subscribe(this.eventsSource);

  private eventsSource = new BehaviorSubject(null);
  private originationsSource = new BehaviorSubject(null);

  public originations$ = this.originationsSource.asObservable();
  public events$ = this.eventsSource.asObservable();
}

应用模块.ts

@NgModule({
  declarations: [...],
  imports: [
    SharedModule.forRoot(),
   ...
  ],
  providers: [...],
  bootstrap: [AppComponent]
})
export class AppModule { }

核心/核心模块.ts

@NgModule({
  declarations:
    [
      CoreComponent,
      ...
    ],
  exports: [
    CoreComponent
  ],
  imports: [
    CoreRoutingModule,
    SharedModule
    ...
  ],
})
export class CoreModule { }

核心/核心组件.ts

@Component({
  selector: 'app-dashboard',
  templateUrl: './dashboard.component.html',
  styleUrls: ['./dashboard.component.scss']
})
export class DashboardComponent implements{

  constructor(public dataStorageService : DataStorageService) { }

}