private function mergeConfigs($key)
    {
        $mergedConfig = [];
        $userConfig = key($this->configs);
        foreach ($this->configs as $config) {
            $mergedConfig = array_merge(isset($config[$key]) ? $config[$key] : [], $mergedConfig);
        }
        $this->configs[$userConfig][$key] = $mergedConfig;
    }