/test-data/samtools_flagstat_out1.txt

 110 in total
 20 QC failure
 30 duplicates
 410 mapped (100.00%)
 50 paired in sequencing
 60 read1
 70 read2
 80 properly paired (nan%)
 90 with itself and mate mapped
100 singletons (nan%)
110 with mate mapped to a different chr
120 with mate mapped to a different chr (mapQ>=5)