{"ast_node_type":"variable","tokens":[{"end":37,"kind":"keyword","start":0,"text":"let"}]}
        let lhs_span = lhs_tt.span();
        check_emission(macro_check::check_meta_variables(&sess.psess, node_id, &lhs_tt, &rhs_tt));
        // Convert the lhs into `MatcherLoc` form, which is better for doing the