怎么给HarmonyOS用户首选项中的数据设置有效期？

type DataType = { value: ValueType | object, expire: number };

class LocalStorage {
   async put(key: string, value: ValueType | object, expire?: Date) {
       const data: DataType = {
           value,
           expire: expire ? expire.getTime() : -1
       };
       const dataStr = JSON.stringify(data);
       await this.preference.put(key, dataStr);
       await this.preference.flush();
   }

   async getValue(key: string): Promise<ValueType | object> {
       if (!this.preference.has(key)) {
           return Promise.resolve(null);
       }
       let value = await this.preference.get(key, '') as string;
       if (isJsonObject(value)) {
           const data: DataType = JSON.parse(value);
           if (data.expire === -1 || data.expire > Date.now()) {
               return Promise.resolve(data.value);
           } else {
               this.preference.delete(key);
           }
       }
       return Promise.resolve(null);
   }
}
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.