true
false
-Reciever is null in rterror_null_receiver_alt4::Sys::(kernel::Sys::main) (alt/rterror_null_receiver_alt4.nit:29)
+Reciever is null (alt/rterror_null_receiver_alt4.nit:29)
,---- Stack trace -- - - -
| rterror_null_receiver_alt4::Sys::(kernel::Sys::main) (alt/rterror_null_receiver_alt4.nit:23)
`------------------- - - -