Known big bugs and limitations

= Primitive types and null  =

Currently, the implementation of primitive types expects their values are not null.
However, the NIT syntax allows null to be assigned to primitive variable and attributes.

Thus, using null and primitive may yield to unexpected results.
A temporal ugly fix to avoid bad surprises is that primitive attribute are implicitly initialized with a non null default value.

Change required:
 - wait nullable
 - remove implicitly initialization

= Closures redefinition =

No checks are done to verify that closure signatures are conform among redefinitions

Change required:
 - add the checks