class PartitionedIndexReader extends AbstractIndexReader {

    @Override
    public IndexSampler createSampler()
    {
        List<IndexSampler> indexSamplers = indexReaders.parallelStream()
                .map( SimpleIndexReader::createSampler )
                .collect( Collectors.toList() );
        return new AggregatingIndexSampler( indexSamplers );
    }

    public  PartitionedIndexReader( List<PartitionSearcher> partitionSearchers,
            IndexDescriptor descriptor,
            IndexSamplingConfig samplingConfig,
            TaskCoordinator taskCoordinator );
      PartitionedIndexReader( IndexDescriptor descriptor, List<SimpleIndexReader> readers );

}