class NormalSwaptionExpiryTenorProvider implements NormalSwaptionProviderInterface, SwaptionSurfaceProvider {

  @Override
  public double getVolatility(double expiry, double tenor, double strikeRate, double forwardRate) {
    return _parameters.getZValue(expiry, tenor);
  }

  public  NormalSwaptionExpiryTenorProvider(final MulticurveProviderInterface multicurve, 
      final Surface<Double, Double, Double> parameters, final GeneratorSwapFixedIbor generator);

}