public static function generateElement(string $tagName,
                                         array $attributes = [],
                                         ?string $innerText = '',
                                         bool $isHtml = false): string
  {
    $html = self::generateTag($tagName, $attributes);
    $html .= ($isHtml) ? $innerText : self::txt2Html($innerText);
    $html .= '</';
    $html .= $tagName;
    $html .= '>';

    return $html;
  }