protected function getAttributesInput(array $attr)
    {
        $output = [];
        foreach ($attr as $key => $values) {
            if (empty($values)) {
                continue;
            }
            if (in_array($key, $this->attributesUnique)) {
                $output[] = $key;
            } elseif (!in_array($key, $this->attributesCss) && $key !== 'selected') {
                $output[] = $key . '="' . $values . '"';
            }
        }
        $implode = implode(' ', $output);

        return $implode
            ? " $implode"
            : '';
    }