{"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
        let longer_than = if let Some(idx) = spec.rfind('>') {
    pub(crate) fn from_spec(mut spec: &str) -> (WriteFilter, Option<FxHashSet<String>>) {
            let longer_than = spec[idx + 1..].parse().expect("invalid profile longer_than");