code: def getStats(self):
          
          stats = protocol.ReadStats()
          stats.aligned_read_count = self.getNumAlignedReads()
          stats.unaligned_read_count = self.getNumUnalignedReads()
          # TODO base_count requires iterating through all reads
          return stats
docs: Returns the GA4GH protocol representation of this read group's
          ReadStats.