/**
  * @inheritdoc
  */
 public function init()
 {
     parent::init();
     if ($this->modelClass === null) {
         throw new InvalidConfigException('The property modelClass can not be empty and is required for FlowActiveWindow.');
     }
 }
 /**
  * @inheritdoc
  */
 public function init()
 {
     parent::init();
     if ($this->tableName === null) {
         throw new Exception("The Active Window tableName property can not be null.");
     }
 }