LdapTools\Utilities\MBString::strtolower PHP Метод

    public static function strtolower($value)
    {
        if (self::isMbstringLoaded()) {
            return mb_strtolower($value, 'UTF-8');
        }
        return strtolower($value);
    }

 /**
  * If any attributes that were requested to be ordered by are not explicitly in the attribute selection, add them.
  *
  * @param array $attributes
  * @param null|string $alias
  * @return array
  */
 protected function mergeOrderByAttributes(array $attributes, $alias = null)
 {
     if (!$this->isWildCardSelection() && !empty($this->orderBy)) {
         $orderBy = $this->getAttributesForAlias(array_keys($this->orderBy), $alias);
         foreach ($orderBy as $attribute) {
             if (!in_array(MBString::strtolower($attribute), MBString::array_change_value_case($attributes))) {
                 $attributes[] = $attribute;
             }
         }
     }
     return $attributes;
 }