Disable column sorting for header

I have a grid which has certain columns displayed under one header. I want to sort on the individual columns but disable sorting on the header. Basically I don’t want to sort on the header but do want it for the subheaders? Is it possible?

Grid has not differ the first and next header rows, so it not possible to allow sorting by one row and deny sorting by other row.
You can try to block event on DOM level, to prevent sorting by clicking on first line of header it will look as

Such code need to be added after grid.init call