{"ast_node_type":"variable","tokens":[{"end":45,"kind":"keyword","start":0,"text":"let"}]}
        let lint_level = lint_level.as_str();
    fn emit_unused_externs(&mut self, lint_level: rustc_lint_defs::Level, unused_externs: &[&str]) {
        let data = UnusedExterns { lint_level, unused_extern_names: unused_externs };