src/vs/base/parts/storage/common/storage.ts/Storage/onDidChangeItemsExternal
class Storage:	private onDidChangeItemsExternal(e: IStorageItemsChangeEvent): void {
		// items that change external require us to update our
		// caches with the values. we just accept the value and
		// emit an event if there is a change.
		e.changed?.forEach((value, key) => this.accept(key, value));
		e.deleted?.forEach(key => this.accept(key, undefined));
	}