code: public boolean isRevoked(final boolean defaultRevocationState) {
          var revoked = true;
          try {
              final var url = getRevocationURL();
              if (url == null) {
                  return false;
              }
              final var con = httpHandler.open(url);
              con.setUseCaches(false);
              if (con instanceof HttpURLConnection) {
                  final var hCon = (HttpURLConnection) con;
                  hCon.connect();
                  return httpHandler.responseCode(hCon) != HttpURLConnection.HTTP_OK;
              }
              return false;
          } catch (final IOException exception) {
              revoked = defaultRevocationState;
          }
          return revoked;
      }
docs: Check if the license is revoked or not. To get the revocation information
  the method tries to issue a http connection (GET) to the url specified in
  the license feature {@code revocationUrl}. If the URL returns anything
  with http status code {@code 200} then the license is not revoked.
  <p>
  The url string in the feature {@code revocationUrl} may contain the place
  holder <code>${licenseId}</code>, which is replaced by the feature value
  {@code licenseId}. This feature makes it possible to setup a revocation
  service and use a constant string in the different licenses.
  <p>
  The method can work in two different ways. One way is to ensure that the
  license is not revoked and return {@code true} only if it is sure that
  the license is revoked or revocation information is not available.
  <p>
  The other way is to ensure that the license is revoked and return
  {@code false} if the license was not revoked or the revocation
  information is not available.
  <p>
  The difference is whether to treat the license revoked when the
  revocation service is not reachable.
  
  @param defaultRevocationState should be {@code true} to treat the license revoked when the
  revocation service is not reachable. Setting this argument
  {@code false} makes the revocation handling more polite: if
  the license revocation service is not reachable then the
  license is treated as not revoked.
  @return {@code true} if the license is revoked and {@code false} if the
  license is not revoked.