The sorting array that is used in many QueryDtos is not nullable in most cases.

This might make trouble when users want to use generated clients because that field is not nullable, so the user might need to supply an empty array each time (depending on the client generation tool, there does not seem to be a problem with the generated Java client).

However, usually all our properties in these query DTOs are nullable to prevent this. Sorting not being nullable could suggest to the user that they need to provide a sorting value, which is not actually the case, as sorting is optional.  

Refactoring this would touch at least 18 ftl files based on a quick count.