/**
  * Кэш ученых степеней
  *
  * @return CArrayList|null
  */
 public static function getCacheDegrees()
 {
     if (is_null(self::$_cacheDegrees)) {
         self::$_cacheDegrees = new CArrayList();
         foreach (CActiveRecordProvider::getAllFromTable(TABLE_DEGREES)->getItems() as $item) {
             $term = new CTerm($item);
             self::$_cacheDegrees->add($term->getId(), $term);
         }
     }
     return self::$_cacheDegrees;
 }