How to use ASPxGridLookup in multiple selection mode as the ASPxGridView editor

This example is an illustration of the Documentation - Add information about the use of the ASPxGridLookup.Value property in Multiple SelectionMode suggestion.

It illustrates how to use ASPxGridLookup in a multiple selection mode (SelectionMode=Multiple) as the ASPxGridView editor.
ASPxGridLookup is bound with an enumerable value containing multiple items.

MVC:
GridView - How to use GridLookup with single selection mode in EditForm
GridView - How to use GridLookup in EditForm in multiple selection mode