protected function do_post()
 {
     if (empty($_POST["student_id"])) {
         $this->exit_error(400, "studentIDMandatoryAndNotEmpty");
     } else {
         if (empty($_POST["team_id"])) {
             $this->exit_error(400, "teamIDMandatoryAndNotEmpty");
         } else {
             $student_id = $_POST["student_id"];
             $team_id = $_POST["team_id"];
             TeamModel::addStudentToTeam($student_id, $team_id);
         }
     }
 }