public function save(WpProQuiz_Model_Category $category)
 {
     $type = $category->getType();
     if ($category->getCategoryId() == 0) {
         $this->_wpdb->insert($this->_tableCategory, array('category_name' => $category->getCategoryName(), 'type' => empty($type) ? 'QUESTION' : $type), array('%s', '%s'));
         $category->setCategoryId($this->_wpdb->insert_id);
     } else {
         $this->_wpdb->update($this->_tableCategory, array('category_name' => $category->getCategoryName()), array('category_id' => $category->getCategoryId()), array('%s'), array('%d'));
     }
     return $category;
 }