protected function getCommandConfig($commandKey)
    {
        if (isset($this->configsPerCommandKey[$commandKey])) {
            return $this->configsPerCommandKey[$commandKey];
        }
        $config = new Config($this->config->get('default')->toArray(), true);
        if ($this->config->__isset($commandKey)) {
            $commandConfig = $this->config->get($commandKey);
            $config->merge($commandConfig);
        }
        $this->configsPerCommandKey[$commandKey] = $config;
        return $config;
    }