/**
     * Remove the key from the store.
     * @param key The key to remove the value from
     */
    public async remove(key: string): Promise<void> {
        await this.lock.promise;

        this.assertNotHistoryMode();
        if (!(await this.localStorage.removeItem(key).toPromise())) {
            throw new Error('Could not delete the item.');
        }
    }

    /**
     * Clear the whole cache
     */
    public async clear(): Promise<void> {
        await this.lock.promise;

        this.assertNotHistoryMode();
        if (!(await this.localStorage.clear().toPromise())) {
            throw new Error('Could not clear the storage.');
        }
    }

 /**
  * Sets the item into the store asynchronously.
  * @param key
  * @param item
  */
 public async set(key: string, item: any): Promise<void> {
     this.assertNotHistroyMode();
     if (item === null || item === undefined) {
         await this.remove(key); // You cannot do a setItem with null or undefined...
     } else {
         if (!(await this.localStorage.setItem(key, item).toPromise())) {
             throw new Error('Could not set the item.');
         }
     }
 }

 /**
  * get a value from the store. You need to subscribe to the request to retrieve the value.
  *
  * TODO: This needs adjustment to ensure safe access.
  * Since angular 7 `LocalStorrage.getItem` will return "unknown" instead of any.
  * https://github.com/cyrilletuzi/angular-async-local-storage/blob/master/docs/MIGRATION_TO_V7.md
  * @param key The key to get the value from
  * @returns The requested value to the key
  */
 public async get<T>(key: string): Promise<T> {
     return await this.localStorage.getUnsafeItem<T>(key).toPromise();
 }

    /**
     * get a value from the store. You need to subscribe to the request to retrieve the value.
     *
     * @param key The key to get the value from
     * @returns The requested value to the key
     */
    public async get<T>(key: string): Promise<T> {
        await this.lock.promise;

        return ((await this.localStorage.getItem<T>(key)) as Observable<T>).toPromise();
    }