{"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"GenericArgData::Ty(ty)"}]}
                GenericArgData::Ty(ty) => GenericArgData::Ty(self.insert_type_vars_shallow(ty)),
            |arg, _| match arg {
                // FIXME: insert lifetime vars once LifetimeData::InferenceVar