{"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"debug!(\"get_var_name_and_span_for_region:"}]}
                debug!("get_var_name_and_span_for_region: attempting argument");
            .or_else(|| {
                self.get_argument_index_for_region(tcx, fr).map(|index| {