{"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"let"}]}
        let Node::GenericParam(param) = tcx.hir_node_by_def_id(*var) else {
    for (var, arg) in bound_vars {
            span_bug!(tcx.def_span(*var), "expected bound-var def-id to resolve to param");