base_isa_gen2.nit:39,8--22: Warning: expression is already a `A[Object]`.
base_isa_gen2.nit:41,8--22: Warning: expression is already a `A[Object]` since it is a `B[Object]`.
base_isa_gen2.nit:42,8--22: Warning: expression is already a `B[Object]`.
base_isa_gen2.nit:44,8--22: Warning: expression is already a `A[Object]` since it is a `C[Object]`.
base_isa_gen2.nit:46,8--22: Warning: expression is already a `C[Object]`.
base_isa_gen2.nit:48,8--22: Warning: expression is already a `A[Object]` since it is a `D[Object, Object]`.
base_isa_gen2.nit:49,8--22: Warning: expression is already a `B[Object]` since it is a `D[Object, Object]`.
base_isa_gen2.nit:50,8--22: Warning: expression is already a `C[Object]` since it is a `D[Object, Object]`.
base_isa_gen2.nit:51,8--30: Warning: expression is already a `D[Object, Object]`.
true