code: public X509Certificate createCertificate(InputStream certRequestInputStream, X509Certificate cert,
          PrivateKey privateKey, int lifetime, int delegationMode, X509ExtensionSet extSet) throws IOException,
          GeneralSecurityException {
          return createCertificate(certRequestInputStream, cert, privateKey, lifetime, delegationMode, extSet, null);
      }
docs: Creates a proxy certificate from the certificate request.
  
  @see #createCertificate(InputStream, X509Certificate, PrivateKey, int, int, X509ExtensionSet, String)
  createCertificate
  @deprecated