class HistoricalShockMarketDataProvider extends AbstractMarketDataProvider {

  @Override
  public void subscribe(ValueSpecification valueSpecification) {
    _historicalProvider1.subscribe(valueSpecification);
    _historicalProvider2.subscribe(valueSpecification);
    _baseProvider.subscribe(valueSpecification);
  }

  public  HistoricalShockMarketDataProvider(MarketDataProvider historicalProvider1,
                                           MarketDataProvider historicalProvider2,
                                           MarketDataProvider baseProvider);

}