Able to create a constraint on a non existing field

I've created a few fields on an entity and add some constraints to those fields. Everything is ok. But when I add a constraint to a field that doesn't exit, then it adds the constraint to the last created field (looks a bit random actually).

So if I type :

[Artist.java]$ constraint-add --onProperty dummy --constraint NotNull
***SUCCESS*** Constraint NotNull successfully configured

dummy doesn't exist, so it adds NotNull to other attributes