{"ast_node_type":"struct","tokens":[{"end":100,"kind":"keyword","start":0,"text":"//"}]}
        // `tracing_separate_thread` is used to instruct the tracing_chrome [tracing::Layer] in Miri
        self.frame_mut().loc = Left(mir::Location::START);
        // to put the "frame" span on a separate trace thread/line than other spans, to make the