The problem with "extra_check" is that it is applied for the whole workspace. In my case I depend on deno which uses ruqlite, huge dependency which can have a lot going on. I do want to have query_row validate that it does not return multiple rows, but I do not really want to interfere with deno in case it relies on this behavior in some way. More preferred way would be to let the user decide at use site whether it should be validated