code: def _get_pltdotstrs(self, hdrgos_usr, **kws):
          
          import datetime
          import timeit
          dotstrs_all = []
          tic = timeit.default_timer()
          # Loop through GO groups. Each group of GOs is formed under a single "header GO"
          hdrgo2usrgos, go2obj = self._get_plt_data(hdrgos_usr)
          # get dot strings with _get_dotstrs_curs
          for hdrgo, usrgos in hdrgo2usrgos.items():
              dotstrs_cur = self._get_dotgraphs(
                  hdrgo, usrgos,
                  pltargs=PltGroupedGosArgs(self.grprobj, **kws),
                  go2parentids=get_go2parents_go2obj(go2obj))
              dotstrs_all.extend(dotstrs_cur)
          sys.stdout.write("\nElapsed HMS: {HMS} to write ".format(
              HMS=str(datetime.timedelta(seconds=(timeit.default_timer()-tic)))))
          sys.stdout.write("{P:5,} GO DAG plots for {H:>5,} GO grouping headers\n".format(
              H=len(hdrgo2usrgos), P=len(dotstrs_all)))
          return sorted(set(dotstrs_all))
docs: Plot GO DAGs for each group found under a specfied header GO.