(int)$model->id, 'lesson' => $model->lesson, 'teacher' => $model->teacher, 'max_student_nums' => $model->max_student_nums, 'student_nums' => $model->student_nums, 'progress' => $model->progress, 'grade' => $model->grade, 'status' => $model->status, 'created_at' => $model->created_at->format(Carbon::DEFAULT_TO_STRING_FORMAT), 'updated_at' => $model->updated_at->format(Carbon::DEFAULT_TO_STRING_FORMAT) ]; } }