private void detach_Quizs(Quiz entity)
 {
     this.SendPropertyChanging();
     entity.Theme = null;
 }
 private void attach_Quizs(Quiz entity)
 {
     this.SendPropertyChanging();
     entity.Theme = this;
 }
 partial void UpdateQuiz(Quiz instance);
 partial void DeleteQuiz(Quiz instance);
 partial void InsertQuiz(Quiz instance);