if(typeof stanza.querySelector === 'function') {
            el = stanza.querySelector(elName);
            txt = el ? el.textContent : null;
        } else if(typeof stanza.getChildText === 'function') {
            txt = stanza.getChildText(elName) || stanza.children.find(child => typeof child.getChildText === 'function' && this.getElementText(child, elName));