gistfile1.cs

//class Application {
public virtual void ReceivePaperVersion(DateTime sendDate,DateTime arrivalDate){
      if(Statuses.ApplicationStatus!=ApplicationStatus.ReceivedElectronically)
        throw new ApplicationException
          ("Paper version can be received only right after electronic version is received.");
      var d=Call.ApplicationDeadlines;
      if(sendDate>d.PaperVersionSendDeadline) 
        throw new ApplicationException("Send date exceeds call deadline");
      if(arrivalDate>d.PaperVersionArrivalDeadline)
        throw new ApplicationException("Arrival date exceeds call deadline");
      PaperVersionDetails=new PaperVersionDetails(sendDate,arrivalDate);
      Statuses.ApplicationStatus=ApplicationStatus.ReceivedFully;
}