function getLang(el, fallback) {
            try {
                return (el.getAttribute("lang"))
                    ? el.getAttribute("lang").toLowerCase()
                    : el.tagName.toLowerCase() === "html"
                        ? fallback
                            ? mainLanguage
                            : null
                        : getLang(el.parentNode, fallback);
            } catch (ignore) {
                return null;
            }
        }
Get language of element by searching its parents or fallback
@param {Object} el The element
@param {boolean} fallback Will falback to mainlanguage
@returns {string|null} The language or null