{"ast_node_type":"variable","tokens":[{"end":37,"kind":"keyword","start":0,"text":"let"}]}
    let dyn_token = ty.impl_token()?;
fn validate_impl_object_ty_plus(ty: ast::ImplTraitType) -> Option<SyntaxError> {
    let preceding_token = algo::skip_trivia_token(dyn_token.prev_token()?, Direction::Prev)?;