{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"err.subdiagnostic(errors::ExpectedReturnTypeLabel::Unit"}]}
                    err.subdiagnostic(errors::ExpectedReturnTypeLabel::Unit { span });
                if !self.can_add_return_type(fn_id) {
                } else if let Some(found) = found.make_suggestable(self.tcx, false, None) {