public function behaviors()
    {
        return [
            'blameable' => [
                'class' => BlameableBehavior::className(),
                'createdByAttribute' => 'createdBy',
                'updatedByAttribute' => 'updatedBy',
            ],
            'timestamp' => [
                'class' => TimestampBehavior::className(),
                'attributes' => [
                    ActiveRecord::EVENT_BEFORE_INSERT => ['createdAt'],
                    ActiveRecord::EVENT_BEFORE_UPDATE => ['updatedAt']
                ]
            ],
            'purify' => [
                'class' => PurifyBehavior::className(),
                'attributes' => ['content']
            ]
        ];
    }