HarmonyOS 接口类怎么得到自己的具体实现类

示例demo：

export interface AService {
}

export interface BService extends AService {
}

export class ServiceImpl implements BService {
}
// 定义工厂类
export class ServiceFactory {
  static createService(): BService {
    // 根据具体情况返回不同的实现类
    return new ServiceImpl();
  }

  static getServiceImpl(service: AService): ServiceImpl {
    if (service instanceof ServiceImpl) {
      return service;
    }
    throw new Error('Provided service is not an instance of ServiceImpl');
  }
}

// 使用示例
import { ServiceFactory, AService, BService, ServiceImpl } from './services';

function installService(service: AService): void {
  try {
    const impl = ServiceFactory.getServiceImpl(service);
    console.log('ServiceImpl对象:', impl);
  } catch (error) {
    console.error(error.message);
  }
}

const service: BService = ServiceFactory.createService();
installService(service);