/**
  * Store a newly created resource in storage.
  *
  * @param  \Illuminate\Http\Request  $request
  * @return \Illuminate\Http\Response
  */
 public function store(Request $request)
 {
     $rule = ['department_id' => 'required', 'subject_id' => 'required', 'group' => 'required'];
     $this->validate($request, $rule);
     $department_subject = new DepartmentSubject($request->all());
     $department_subject->save();
     return redirect('admin/department_subject/create')->with('status', "Subject assign successfully");
 }