the wanted behavior is that I want to sort 3 columns with multi sort functionality of the grid, but the problem is that two of my columns are build from objects and the multi sort is not working over them.
This is the example https://jsfiddle.net/x3Lqn2h3/
So, try first to sort over "age" descending (it works) after that try to sort over "name" (it works) and finally sort over "address" (it does not work). When you click over address the values "Pernik" and "Silistra" should swap their places but they don't.
Thank you for your help in advance!