{"ast_node_type":"variable","tokens":[{"end":57,"kind":"keyword","start":0,"text":"let"}]}
    let mut result: ArenaMap<LocalId, MutabilityReason> =
) -> ArenaMap<LocalId, MutabilityReason> {
        body.locals.iter().map(|it| (it.0, MutabilityReason::Unused)).collect();