HarmonyOS navigation有单例模式吗

参考示例如下：

pushPathsingleTask(info: NavPathInfo, animated?: boolean): void {
  this.pageArray =[]
  this.pageArray = this.pageInfos.getIndexByName(info.name)
  if(this.pageArray.length == 0){
  this.pageInfos.pushPath(info, animated)
  return;
  }
  this.pageInfos.popToIndex(this.pageArray.pop(), animated)
}

navigation launchmode说明参考文档：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/ts-basic-components-navigation-V5#launchmode12枚举说明