public function getfirst($typeid, $uuid)
 {
     // to get first element matching based on uuid
     switch ($typeid) {
         case 0:
             //Course
             return Course::where('id', $uuid)->first();
         case 1:
             //Subject
             # code...
             return Subject::where('id', $uuid)->first();
         case 2:
             //Module
             # code...
             return Module::where('id', $uuid)->first();
         case 3:
             //Cha[ter]
             # code...
             return Chapter::where('id', $uuid)->first();
         case 4:
             //Topic
             # code...
             return Topic::where('id', $uuid)->first();
         default:
             # code...
             break;
     }
 }
 public function getmodules($subjectid)
 {
     return Module::where('ref_id', $subjectid)->get();
 }