class RequestHedgingProxyProvider extends
        ConfiguredFailoverProxyProvider<T> {

  @Override
  public synchronized void performFailover(T currentProxy) {
    toIgnore = successfulProxy.proxyInfo;
    successfulProxy = null;
  }

  public  RequestHedgingProxyProvider(
          Configuration conf, URI uri, Class<T> xface);
  @VisibleForTesting  RequestHedgingProxyProvider(Configuration conf, URI uri,
                              Class<T> xface, ProxyFactory<T> factory);

}