/**
  * @param $user
  * @param $data
  * @return mixed
  * @throws UserNotFound
  * @throws ValidationException
  */
 public function updateExistingUser($user, $data)
 {
     $user->first_name = $data['first_name'];
     $user->last_name = $data['last_name'];
     $user->email = $data['email'];
     if ($data['password'] && $data['password'] !== '') {
         $user->password = $this->hasher->make($data['password']);
     }
     $user->save();
     return $user;
 }