/**
  * Display the specified resource.
  *
  * @param  int  $id
  * @return \Illuminate\Http\Response
  */
 public function show($encadrantId = null, $stageId = null, $studentId = null)
 {
     //afficher all student of specifique encadrant of specifique stage of a specifique encadrant
     if (is_null($studentId)) {
         return Encadrant_Stage_Etudiant::join('Etudiant', 'Etudiant.id_Etudiant', '=', 'Encadrant_Stage_Etudiant.id_Etudiant')->select('Etudiant.*')->where('Encadrant_Stage_Etudiant.id_Enseignant', '=', $encadrantId)->where('Encadrant_Stage_Etudiant.id_Stage', '=', $stageId)->distinct()->get();
     } else {
         $etudiant = Etudiant::find($studentId);
         return is_null($etudiant) ? response()->json(['error' => 'etudiant Note not found'], HttpResponse::HTTP_NOT_FOUND) : $etudiant;
     }
 }