{"ast_node_type":"variable","tokens":[{"end":88,"kind":"keyword","start":0,"text":"let"}]}
                    let lifetime = ec.lower_lifetime_ref_opt(lifetime_param.lifetime());
                ast::GenericParam::LifetimeParam(lifetime_param) => {
                    if let LifetimeRef::Named(name) = &ec.store.lifetimes[lifetime] {