- introspect_write_arguments(i, v->x.method.signature, "in");
- introspect_write_arguments(i, v->x.method.result, "out");
+ introspect_write_arguments(i, strempty(v->x.method.signature), "in");
+ introspect_write_arguments(i, strempty(v->x.method.result), "out");