private static (int ClassId, string ClassRegistrationEventTarget) ParseClassIdAndRegistrationEventTarget(IHtmlTableRowElement classRow)
{
int courseId = int.Parse(classRow.QuerySelector <IHtmlSpanElement>(slc_classId).TextContent);
int classSection = int.Parse(classRow.QuerySelector <IHtmlSpanElement>(slc_classSection).TextContent);
string registrationAnchorHref = classRow.QuerySelector <IHtmlAnchorElement>("a[id*=btnAddCourse]").Href;
int hrefFirstQuoteIndex = registrationAnchorHref.IndexOf('\''), hrefSecondQuoteIndex = registrationAnchorHref.IndexOf('\'', hrefFirstQuoteIndex + 1);
string registrationEventTarget = registrationAnchorHref.Substring(hrefFirstQuoteIndex + 1, hrefSecondQuoteIndex - hrefFirstQuoteIndex - 1);
return(UClass.Identify(courseId, classSection), registrationEventTarget);
}