{"ast_node_type":"variable","tokens":[{"end":55,"kind":"keyword","start":0,"text":"let"}]}
    let type_di_node = type_di_node(cx, variable_type);
    let variable_type = Instance::mono(cx.tcx, def_id).ty(cx.tcx, cx.typing_env());
    let var_name = tcx.item_name(def_id);