SqlStorage in alpha 51

Hi all,

I've just updated my project to alpha 51, but when I run my project the console gives me this error:
constructor(options={}) not implemented for this storage engine

This piece of code seems to cause this error:
this.storage = new Storage(SqlStorage, {name: 'myapp'});

my import:
import {Storage, SqlStorage} from 'ionic/ionic';

ionic info:

Is there something wrong in my code or is it an alpha issue?

thanks in advance!

Tristan