public function update($user)
    {
        $user = User::find($user);
        if (!$user) {
            return redirect_to_resource();
        }

        $attributes = request()->validate([
            'firstname' => 'required',
            'lastname'  => 'required',
            'cellphone' => 'required',
            'telephone' => 'nullable',
            'born_at'   => 'nullable',
            'etokens'   => 'nullable',
            'email'     => 'required|email|' . Rule::unique('users')->ignore($user->id),
            'roles'     => 'required|array',
        ]);

        unset($attributes['roles']);

        $this->updateEntry($user, $attributes);

        $user->roles()->sync(input('roles'));

        return redirect_to_resource();
    }