ASPxDashboardDesigner - How to save dashboards to a data base

This example shows how to create a custom dashboard storage that allows storing dashboards in a data base.
Custom dashboard storage should implement the IDashboardStorage interface, that contains the following public methods:

string CreateNewDashboard() - creates a new dashboard and saves it to a storage. Returns an ID of the created dashboard.
XDocument GetDashboard(string id) - returns a dashboard by its id in the  XDocument format that describes an object model of the dashboard. 
IEnumerable<string> GetDashboardIDs() - returns a list of IDs of dashboards available in the data storage .
void UpdateDashboard(string id, XDocument document) - updates the dashboard by its id with new settings.