code: protected void extendsTBSCertificate(BcX509TBSCertificateBuilder builder, CertifiedPublicKey issuer,
          PrincipalIndentifier subjectName, PublicKeyParameters subject, X509CertificateParameters parameters)
          throws IOException
      {
          // Do nothing by default.
      }
docs: Extend TBS certificate depending of certificate version.
  
  @param builder the X.509 TBS certificate builder received from #getTBSCertificateBuilder().
  @param issuer the certified public key of the issuer of the certificate, or null for self signed one.
  @param subjectName the subject name.
  @param subject the subject public key.
  @param parameters the X.509 certificate parameters.
  @throws IOException on encoding error.