PayWithAmazon\Client::calculateSignatureAndPost PHP Method

    private function calculateSignatureAndPost($parameters)
    {
        // Call the signature and Post function to perform the actions. Returns XML in array format
        $parametersString = $this->calculateSignatureAndParametersToString($parameters);
        // POST using curl the String converted Parameters
        $response = $this->invokePost($parametersString);
        // Send this response as args to ResponseParser class which will return the object of the class.
        $responseObject = new ResponseParser($response);
        return $responseObject;
    }