getPropertyText(xml, property) {
    var el = Object(core["qsp"])(xml, "meta", {
      "property": property
    });

    if (el && el.childNodes.length) {
      return el.childNodes[0].nodeValue;
    }

    return "";
  }
Get text by property
@private
@param  {node} xml
@param  {string} property
@return {string} text