public void Remove(User user)
 {
     if (this._collection.Contains(user))
         this._collection.Remove(user);
 }
 public NewUserEventArgs(string username, string userUniqueID)
 {
     this._user = new User(username, userUniqueID);
 }
 public void Add(User user)
 {
     if (!this._collection.Contains(user))
         this._collection.Add(user);
 }