protected function _checkProvider($data)
    {
        $fields = $this->_config['fields'];

        if (empty($data[$fields['provider']])) {
            return false;
        }

        $provider = $data[$fields['provider']];

        if ($provider === 'OpenID' && empty($data[$fields['openid_identifier']])) {
            return false;
        }

        return $provider;
    }