jqxgrid selectionmode checkbox check already selected checked checkbox or selected checkboxes

I am using similar kind of jqx grid shown in below link. My concern is how will have show already selected check boxes ? Let say I show countries, already i have choosen 2 countries earlier i want to shown them as checked and allow user to do more selection of countries. Please help

Thx

https://www.jqwidgets.com/jquery-widgets-demo/demos/jqxgrid/index.htm#demos/jqxgrid/checkboxselection.htm