public function testSignature()
 {
     foreach (Environment::$ALLOWED_HASHES as $hash) {
         $this->environment->setHashAlgorithm($hash);
         $payment = $this->getRandomPayment();
         $parameters = $payment->getParameters()->getAll();
         $fields = $payment->getForm()->getHiddenFields();
         $hash = $this->createHash($parameters, $this->environment->getShaIn(), $this->environment->getHashAlgorithm());
         $this->assertEquals($fields[Parameter::SIGNATURE], $hash);
     }
 }