rf3main/backend/modules/common/Module.php

<?php

namespace backend\modules\common;

/**
 * common module definition class
 */
class Module extends \yii\base\Module
{
    /**
     * {@inheritdoc}
     */
    public $controllerNamespace = 'backend\modules\common\controllers';

    /**
     * {@inheritdoc}
     */
    public function init()
    {
        parent::init();
    }
}