{"ast_node_type":"variable","tokens":[{"end":46,"kind":"keyword","start":0,"text":"let"}]}
            let def = match param.parent(db) {
        if let Definition::GenericParam(hir::GenericParam::LifetimeParam(param)) = self {
                hir::GenericDef::Function(it) => it.source(db).map(|src| src.syntax().cloned()),