Masterpage initializeculture no suitable method found to override error

public partial class BasicMasterPage : System.Web.UI.MasterPage
{
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
{
    if (e.Day.IsToday)
    {
        e.Cell.Style.Add("background-color", "#3556bf");
        e.Cell.Style.Add("font-weight", "bold");
    }
}
Dictionary<string, System.Globalization.Calendar> Calendars =
    new Dictionary<string, System.Globalization.Calendar>()
    {
        {"GregorianCalendar", new GregorianCalendar()},
        {"HebrewCalendar", new HebrewCalendar()},
        {"HijriCalendar", new HijriCalendar()},
        {"JapaneseCalendar", new JapaneseCalendar()},
        {"JulianCalendar", new JulianCalendar()},
        {"KoreanCalendar", new KoreanCalendar()},
        {"TaiwanCalendar", new TaiwanCalendar()},
        {"ThaiBuddhistCalendar", new ThaiBuddhistCalendar ()}
    };

protected override void InitializeCulture()
{
    if (Request.Form["LocaleChoice"] != null)
    {
        string selected = Request.Form["LocaleChoice"];
        string[] calendarSetting = selected.Split('|');
        string selectedLanguage = calendarSetting[0];

        CultureInfo culture = CultureInfo.CreateSpecificCulture(selectedLanguage);

        if (calendarSetting.Length > 1)
        {
            string selectedCalendar = calendarSetting[1];
            var cal = culture.Calendar;
            if (Calendars.TryGetValue(selectedCalendar, out cal))
                culture.DateTimeFormat.Calendar = cal;
        }

        Thread.CurrentThread.CurrentCulture = culture;
        Thread.CurrentThread.CurrentUICulture = culture;
    }
    base.InitializeCulture();
}
}