final SAMRecord srec1 = createSamRecord(header, baseName, frec1, true) ;
srec1.setFirstOfPairFlag(true);
srec1.setSecondOfPairFlag(false);
writer.addAlignment(srec1);
progress.record(srec1);
final SAMRecord srec2 = createSamRecord(header, baseName, frec2, true) ;
srec2.setFirstOfPairFlag(false);
srec2.setSecondOfPairFlag(true);
writer.addAlignment(srec2);