public function crossRefSession(Request $request)
{
$data = $request->all();
$sessions = StudySession::select(['study_sessions.*', 'user_classes.*', 'study_sessions.id as study_id'])->join('user_classes', 'user_classes.class_id', '=', 'study_sessions.class_id')->where('user_classes.user_id', $data['user_id'])->where('study_sessions.status', '<', 2)->orderBy('study_sessions.time_start', 'desc')->get();
return response()->json($sessions);
}