1 base_as_notnull.nit:41,6--19: Warning: expression is already not null, since it is a `A`.
2 base_as_notnull.nit:42,6--20: Warning: expression is already not null, since it is a `A`.
3 base_as_notnull.nit:43,6--19: Warning: expression is already not null, since it is a `B`.
4 base_as_notnull.nit:52,6--19: Warning: expression is already not null, since it is a `B`.