The CertStatusReqItemV2 class should not implement the StatusRequest interface. This was left over from a prototype of OCSP stapling. Things worked because the class needed (and still needs) to have length() and send() methods. But a CertStatusReqItemV2 isn't a StatusRequest like OCSPStatusRequest is and therefore the "implements" definition should be removed. It also allows us to reduce the visibility of the length and send methods to package-private.