internal static Calendar ReadOnly(Calendar calendar)
{
if (calendar == null) { throw new ArgumentNullException("calendar"); }
Contract.EndContractBlock();
if (calendar.IsReadOnly) { return (calendar); }
Calendar clonedCalendar = (Calendar)(calendar.MemberwiseClone());
clonedCalendar.SetReadOnlyState(true);
return (clonedCalendar);
}