public function get($name)
    {
        if (!is_string($name)) {
            throw new \InvalidArgumentException(self::MSG_EXTENSION_NAME, 220);
        }
    
        if (!$this->offsetExists(strtolower($name))) {
            throw new \LogicException(sprintf(self::MSG_NO_EXTENSION_TOGET, $name), 221);
        }
        
        return parent::offsetGet(strtolower($name));
    }