private function renderGroup(array $group)
    {
        if (empty($group)) {
            return '';
        }
        if ($this->groupType === self::GROUP_TYPE_EACH) {
            return implode(PHP_EOL, array_map(function ($namespace) {
                return 'use ' . $namespace . ';';
            }, $group));
        } elseif ($this->groupType === self::GROUP_TYPE_ONE) {
            $group = implode(',' . PHP_EOL . '    ', $group);

            return 'use ' . $group . ';';
        }
    }