OphCoTherapyapplication_DecisionTreeNode::model PHP Method

    public static function model($className = __CLASS__)
    {
        return parent::model($className);
    }

 public function getRootNode()
 {
     $criteria = new CDbCriteria();
     $criteria->addColumnCondition(array('decisiontree_id' => $this->id, 'parent_id' => null));
     $node = OphCoTherapyapplication_DecisionTreeNode::model()->find($criteria);
     return $node;
 }