yii\base\Application::coreComponents PHP Method

    public function coreComponents()
    {
        return ['log' => ['class' => 'yii\\log\\Dispatcher'], 'view' => ['class' => 'yii\\web\\View'], 'formatter' => ['class' => 'yii\\i18n\\Formatter'], 'i18n' => ['class' => 'yii\\i18n\\I18N'], 'mailer' => ['class' => 'yii\\swiftmailer\\Mailer'], 'urlManager' => ['class' => 'yii\\web\\UrlManager'], 'assetManager' => ['class' => 'yii\\web\\AssetManager'], 'security' => ['class' => 'yii\\base\\Security']];
    }

 /**
  * @inheritdoc
  */
 public function coreComponents()
 {
     return array_merge(parent::coreComponents(), ['request' => ['class' => 'yii\\web\\Request'], 'response' => ['class' => 'yii\\web\\Response'], 'session' => ['class' => 'yii\\web\\Session'], 'user' => ['class' => 'yii\\web\\User'], 'errorHandler' => ['class' => 'yii\\web\\ErrorHandler']]);
 }