private function _checkVariables() {
	    // Check to make sure that the $databaseComponent is a string
        if (! is_string($this->databaseComponent)) {
            throw new InvalidConfigException("Image Manager Component - Init: Database component '$this->databaseComponent' is not a string");
        }

        // Check to make sure that the $databaseComponent object exists
        if (Yii::$app->get($this->databaseComponent, false) === null) {
            throw new InvalidConfigException("Image Manager Component - Init: Database component '$this->databaseComponent' does not exists in application configuration");
        }

        // Check to make sure that the $databaseComponent is a yii\db\Connection object
        if (($databaseComponentClassName = get_class(Yii::$app->get($this->databaseComponent))) !== ($connectionClassName = Connection::className())) {
            throw new InvalidConfigException("Image Manager Component - Init: Database component '$this->databaseComponent' is not of type '$connectionClassName' instead it is '$databaseComponentClassName'");
        }
    }