public function getUniqueName()
    {
        $key = 'uniq';

        // Lazy initialization
        if (!isset($this->container[$key])) {
            $extension = $this->getExtension();

            // If extension avaiable, use it
            if ($extension) {
                $name = sprintf('%s.%s', uniqid(), $extension);
            } else {
                // Otherwise just filename without extension
                $name = uniqid();
            }

            $this->container[$key] = $name;
        }

        return $this->container[$key];
    }