Generated base model class overwrites parent behaviors

[leovujanic]

Behaviors method in the generated base model class doesn't call parent method, and there is an option to use different Base Class than e.g. yii\db\ActiveRecord. So, if you extend a class that has some of the behaviors already defined they will be overwritten. I believe that behaviors defined in generated base class should be merged with those defined in the parent class.

[leovujanic]

I would like to have the option to include parent rules and parent behaviours if choose so in generator.

Current state is

public function behaviors()
    {
        return [
            [
                'class' => TimestampBehavior::className(),
            ],
        ];
    }

What I would like to have is

public function behaviors()
    {
        return ArrayHelper::merge(
            parent::behaviors(),
            [
                [
                    'class' => TimestampBehavior::className(),
                ],
        ]);
    }