commas in the output of keys in estat

[sebroy]

delphix@guild:~$ sudo estat backend-io 1
11/19/19 - 18:57:40 UTC

 Tracing enabled... Hit Ctrl-C to end.
   microseconds                                                  read ,
value range                 count ------------- Distribution -------------
[100, 200)                      1 |@

   microseconds                                                 write ,
value range                 count ------------- Distribution -------------
[500, 600)                      4 |@@@@@@@@@@@@@@@@@@
[700, 800)                      2 |@@@@@@
[800, 900)                      1 |@

                                       iops(/s)  avg latency(us)       stddev(us)  throughput(k/s)
 read ,                                       1              150                0                0
 write ,                                      7              638            12865               92


                                       iops(/s)  throughput(k/s)
 total                                        8               92

There are commas after read and write both at the top of each histogram, and at the start of each summary line.