{"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
    let default_ident = cx.std_path(&[kw::Default, sym::Default, kw::Default]);
    // Note that `kw::Default` is "default" and `sym::Default` is "Default"!
    cx.expr_call_global(span, default_ident, ThinVec::new())