PayWithAmazon\ClientTest::testSignature PHP Method

    public function testSignature()
    {
        $client = new Client($this->configParams);
        $parameters['SellerId'] = $this->configParams['merchant_id'];
        $parameters['AWSAccessKeyId'] = $this->configParams['access_key'];
        $parameters['Version'] = 'test';
        $parameters['SignatureMethod'] = 'HmacSHA256';
        $parameters['SignatureVersion'] = 2;
        $parameters['Timestamp'] = $this->getFormattedTimestamp();
        uksort($parameters, 'strcmp');
        $signatureObj = new Signature($this->configParams, $parameters);
        $expectedSignature = $signatureObj->getSignature();
        $this->callPrivateMethod($client, 'createServiceUrl', null);
        $signature = $this->callPrivateMethod($client, 'signParameters', $parameters);
        $this->assertEquals($signature, $expectedSignature);
    }