{"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"SelfKind::Region(lifetime,"}]}
                    SelfKind::Region(lifetime, Mutability::Not)
                    let lifetime = has_lifetime.then(|| self.expect_lifetime());
                } else if is_isolated_mut_self(self, skip_lifetime_count + 1) {