new GenomeLocParser(header.getSequenceDictionary()),
false,
ValidationStringency.SILENT,
ReadShard.DEFAULT_MAX_READS, // reset ReadShard.MAX_READS to ReadShard.DEFAULT_MAX_READS for each test
downsamplingMethod,
new ValidationExclusion(),
new ArrayList<ReadFilter>(),
false);
Iterable<Shard> shardIterator = dataSource.createShardIteratorOverAllReads(new ReadShardBalancer());