{"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
        let primal_call = gen_primal_call(ecx, span, primal, idents, generics);
        let blackbox_call_expr = ecx.expr_path(ecx.path(span, blackbox_path));
        let black_box_primal_call = ecx.expr_call(