{"ast_node_type":"variable","tokens":[{"end":78,"kind":"keyword","start":0,"text":"let"}]}
        let blackbox_call_expr = ecx.expr_path(ecx.path(span, blackbox_path));
        let unsf_expr = ecx.expr_block(P(unsf_block));
        let primal_call = gen_primal_call(ecx, span, primal, idents, generics);