Are you sure the assignment to $code is correct as $response->getCode() targeting Omnipay\Common\Message\AbstractResponse::getCode() seems to always return null.
This check looks for function or method calls that always return null and whose
return value is assigned to a variable.
Are you sure the assignment to $reference is correct as $response->getTransactionReference() targeting Omnipay\Common\Message\A...tTransactionReference() seems to always return null.
This check looks for function or method calls that always return null and whose
return value is assigned to a variable.
This check looks for parameters that have been defined for a function or method, but which are not used in the method body.