private GATKSAMRecord makeRead() {
final SAMReadGroupRecord rg = header.getReadGroups().get(0);
final String readName = String.format("%s.%d.%s", "read", readI, rg.getId());
final GATKSAMRecord read = ArtificialSAMUtils.createArtificialRead(header, readName, 0, 1, readLength);
read.setReadGroup(new GATKSAMReadGroupRecord(rg));
if ( payloadInBytes > 0 )
// add a payload byte array to push memory use per read even higher
read.setAttribute("PL", new byte[payloadInBytes]);
return read;
}