Add DOH tests for _StoreMixin to verify column.set() method now works with subRows.
Add DOH tests for _StoreMixin to verify column.set() method now works with subRows.

dylans/dgrid,dylans/dgrid,kfranqueiro/dgrid,maier49/dgrid,kfranqueiro/dgrid,maier49/dgrid,maier49/dgrid,kfranqueiro/dgrid,dylans/dgrid