{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
        let span = info_span!("frame", tracing_separate_thread = Empty, frame = %instance);
        // [tracing::field::Empty] so that other tracing layers (e.g. the logger) will ignore it.
        self.frame_mut().tracing_span.enter(span);