public function login($credentials)
{
$this->_credentials = $credentials;
$this->_client = new \Oara\Curl\Access($credentials);
$user = $this->_credentials['user'];
$password = $this->_credentials['password'];
$loginUrl = 'http://publisher.tradedoubler.com/pan/login';
$valuesLogin = array(new \Oara\Curl\Parameter('j_username', $user), new \Oara\Curl\Parameter('j_password', $password));
$urls = array();
$urls[] = new \Oara\Curl\Request($loginUrl, $valuesLogin);
$this->_client->post($urls);
}