/**
  * Update the specified resource in storage.
  *
  * @param  int $id
  *
  * @return Response
  */
 public function update($id, $inputs = null, $callback = null)
 {
     if ($inputs === null) {
         $inputs = Request::json()->all();
     }
     $modelName = $this->modelName;
     $model = $modelName::find($id);
     if (empty($model)) {
         return Response::json($model, 404);
     }
     return $this->save($model, $inputs, 'update', $callback);
 }