code: public void showMessage( final ClientRuntimeError error) {
          StringBuilder result = new StringBuilder(DataSetExplorerConstants.INSTANCE.error());
          
          if (error != null) {
              final String message = error.getMessage();
              Throwable t = error.getRootCause();
              String localizedMessage = t != null ? t.getLocalizedMessage() : null;
              result = new StringBuilder(message);
              if (localizedMessage != null) {
                  result.append(" ").append(DataSetExplorerConstants.INSTANCE.cause()).
                          append(": ").append(localizedMessage);
              }
          }
          
          showMessage(result.toString());
      }
docs: Shows the given message in a modal popup that appears above all other workbench contents.
  // TODO: Improve generated message by getting intermediate exception cause messages.
  @param error The client runtime error.