vl_api_prefix_t *pfx = va_arg (*args, vl_api_prefix_t *);
if (unformat (input, "%U/%d", unformat_vl_api_address, &pfx->address,
vl_api_prefix_t *pfx = va_arg (*args, vl_api_prefix_t *);
if (unformat (input, "%U/%d", unformat_vl_api_address, &pfx->address,