code: def _init_prtfmt(self, key="fmta"):
          
          prtfmt = self.gosubdag.prt_attr[key]
          return prtfmt.replace("{NS}", "{NS} {hdr1usr01:2} {num_usrgos:>4} uGOs")
docs: Return print format for Grouper, which includes hdr1usr01 and num_usrgos.