protected function removeExtensionFromFilename($filename, $extension)
    {
        $extension = '.'.$extension;
        $extension_length = mb_strlen($filename) - mb_strlen($extension);
        if (mb_strrpos($filename, $extension) === $extension_length) {
            $filename = mb_substr($filename, 0, $extension_length);
        }

        return $filename;
    }