code: private void updateState(X509Certificate currCert)
          throws CertPathValidatorException
      {
          PublicKey cKey = currCert.getPublicKey();
          if (debug != null) {
              debug.println("BasicChecker.updateState issuer: " +
                  currCert.getIssuerX500Principal().toString() + "; subject: " +
                  currCert.getSubjectX500Principal() + "; serial#: " +
                  currCert.getSerialNumber().toString());
          }
          if (PKIX.isDSAPublicKeyWithoutParams(cKey)) {
              // cKey needs to inherit DSA parameters from prev key
              cKey = makeInheritedParamsKey(cKey, prevPubKey);
              if (debug != null) debug.println("BasicChecker.updateState Made " +
                                               "key with inherited params");
          }
          prevPubKey = cKey;
          prevSubject = currCert.getSubjectX500Principal();
      }
docs: Internal method to manage state information at each iteration