/**
  * @param Request $request
  * @param Response $response
  * @return string
  */
 public function index($request, $response)
 {
     try {
         Student::setRegistry($this->registry);
         $students = Student::findAll();
         $response->setParams(array("students" => $students));
         return "students";
     } catch (ModelException $e) {
         $response->setParams(array("exception" => $e->getMessage()));
         $response->sendRedirect("error");
     }
 }