/**
* Get the headers associated to this request
*
* @return array Array of headers strings
*/
public function getHeaders()
{
$digest = Klarna::digest(Klarna::colon($this->config['eid'], $this->params['currency'], $this->config['secret']));
return array("Accept: {$this->accept}", "Authorization: xmlrpc-4.2 {$digest}");
}