public function authorize(array $userParameters = array())
{
$parameters = array_merge($userParameters, array('type' => 'web_server', 'client_id' => $this->_client->getClientKey(), 'redirect_uri' => $this->_client->getCallbackUrl(), 'response_type' => 'code'));
if ($this->_scope) {
$parameters['scope'] = $this->_scope;
}
$url = $this->_configuration->getAuthorizeEndpoint();
$url .= (strpos($url, '?') !== false ? '&' : '?') . http_build_query($parameters);
header('Location: ' . $url);
die;
}