private function calculateSignatureAndParametersToString($parameters = array())
{
$parameters['AWSAccessKeyId'] = $this->config['access_key'];
$parameters['Version'] = self::SERVICE_VERSION;
$parameters['SignatureMethod'] = 'HmacSHA256';
$parameters['SignatureVersion'] = 2;
$parameters['Timestamp'] = $this->getFormattedTimestamp();
uksort($parameters, 'strcmp');
$this->createServiceUrl();
$parameters['Signature'] = $this->signParameters($parameters);
$parameters = $this->getParametersAsString($parameters);
// Save these parameters in the parameters variable so that it can be returned for unit testing.
$this->parameters = $parameters;
return $parameters;
}