code: def prt_summary(self, prt=sys.stdout):
          
          # Grouping summary
          fmtstr = "Grouped: {U:3,} User GOs, using {h:2,} of {H:,} Grouping GOs, for run: {NAME}\n"
          prt.write(fmtstr.format(
              NAME=self.grpname,
              U=len(self.usrgos),
              h=len(self.hdrobj.hdrgos.intersection(self.hdrgo2usrgos.keys())),
              H=self.hdrobj.num_hdrgos()))
docs: Print summary of grouping/sorting run.