/**
  * Associate matters.
  *
  * @param  AssociateMatterRequest $request
  * @param  int           $teacher_id
  * @return array
  */
 public function associateMatters(AssociateMatterRequest $request, $teacher_id)
 {
     $teacher = $this->repo->get($teacher_id);
     $this->repo->associateMatters($teacher, $request->only('matters'));
     return ['status' => 'ok'];
 }