public function student($announcement_id)
 {
     $student_id = Student::pluck('username', 'id');
     $announcement = Announcement::with('students')->findOrFail($announcement_id);
     return view('announcements::student', compact('announcement', 'student_id'));
 }
 public function create()
 {
     $codes = ["" => ""] + Student::pluck('username', 'username')->toArray();
     return view('callinglog::create', compact('codes'));
 }