public function password($oldPassword, $newPassword)
    {
        if ($this->check()) {
            return $this->matrix()->request('POST', $this->endpoint('account/password'), [
                'auth' => [
                    'type' => 'm.login.password',
                    'user' => $this->data['user_id'],
                    'password' => $oldPassword
                ],
                'new_password' => $newPassword
            ], [
                'access_token' => $this->data['access_token']
            ]);
        }
        throw new \Exception('Not authenticated');
    }