how order Arel:Node:union

I don`t want to use ‘findbysql’, but currently it is the only way to get ordered relation for pagination. It would be good to use ‘last’ and ‘first’ methods.

I have modelname.where(…).union(modelname.where(…)) how i can get something like modelname.where(…).union(modelname.where(…)).order(‘something’)?