public function addLecture(LectureInputModel $model) : ServiceResponse { $lecture = new Lecture($model->getTitle(), $model->getDescription(), $model->getStartDate(), $model->getEndDate(), $model->getConferenceId(), null, null); $this->dbContext->getLecturesRepository()->add($lecture); $this->dbContext->saveChanges(); return new ServiceResponse(null, "Lecture created successfully."); }