gistfile1.cs

  public class Show{
    public Show(DateTime startsOn, DateTime endsOn, string location, ShowType showType){
      StartsOn = startsOn;
      EndsOn = endsOn;
      Location = location;
      ShowType = showType;
      Speakers = new List<Speaker>();
      Attendees = new List<Attendee>();
      AssociatedCampaigns = new List<Campaign>();
    }
    public DateTime StartsOn  { get; set; }
    public DateTime EndsOn  { get; set; }
    public string Location { get; set; }
    public ShowType ShowType { get; set; }
    public string Agenda { get; set; }
    public bool IsCanceled { get; set; }
    public ICollection<Speaker> Speakers { get; set; }
    public ICollection<Attendee> Attendees { get; set; }
    public ICollection<Campaign> AssociatedCampaigns { get; set; }
    public void AssignSpeaker(Speaker speaker){
      Speakers.Add(speaker);
    }
    public void WithdrawSpeaker(Speaker speaker){
      Speakers.Remove(speaker);
    }
    public void RegisterAttendee(Attendee attendee){
      Attendees.Add(attendee);
    }
    public void WithdrawAttendee(Attendee attendee){
      Attendees.Remove(attendee);
    }
    public void PromoteCampaign(Campaign campaign){
      AssociatedCampaigns.Add(campaign);
    }
    public void DisassociateCampaign(Campaign campaign){
      AssociatedCampaigns.Remove(campaign);
    }
    public void Cancel(){
      IsCanceled = true;
    }
  }
  public enum ShowType{ Exhibition, Conference, TradeShow }
  public class Campaign{
    public Campaign(DateTime startsOn, DateTime endsOn){
      StartsOn = startsOn;
      EndsOn = endsOn;
    }
    public DateTime StartsOn  { get; set; }
    public DateTime EndsOn  { get; set; }
  }
  public class Attendee{}
  public class Speaker{}