If xdLocalstore was not init, throwing an error before return of promise will cause it to fail immediately.
If xdLocalstore was not init, throwing an error before return of promise will cause it to fail immediately.

This allows it to fail gracefully in a Promise-like manner, in order for developer to handle rejection in their own particular way

KamiHQ/cross-domain-local-storage,KamiHQ/cross-domain-local-storage