code: public static X500Principal getIssuerX500Principal(X509Certificate cert) {
          try {
              return getX500Principal(cert, true);
          } catch (Exception e) {
              throw new RuntimeException("Could not parse issuer", e);
          }
      }
docs: Extract the issuer X500Principal from an X509Certificate.
  Called from java.security.cert.X509Certificate.getIssuerX500Principal().