private DateTime GetDateHeaderHelper(string headerName)
{
#if DEBUG
using (DebugThreadTracking.SetThreadKind(ThreadKinds.User | ThreadKinds.Async)) {
#endif
string headerValue = _webHeaderCollection[headerName];
if (headerValue == null)
{
return DateTime.MinValue; // MinValue means header is not present
}
return StringToDate(headerValue);
#if DEBUG
}
#endif
}