alt/base_as_notnull_alt2.nit:41,6: Warning: expression is not null, since it is a `A`. alt/base_as_notnull_alt2.nit:42,6--7: Warning: expression is not null, since it is a `A`. alt/base_as_notnull_alt2.nit:43,6: Warning: expression is not null, since it is a `B`. alt/base_as_notnull_alt2.nit:51,6--7: Warning: expression is not null, since it is a `A`. alt/base_as_notnull_alt2.nit:51,6--20: Type error: expected B, got A alt/base_as_notnull_alt2.nit:52,6: Warning: expression is not null, since it is a `B`.