code: def get_sorted_nts_omit_section(self, hdrgo_prt, hdrgo_sort):
          
          nts_flat = []
          # print("SSSS SorterNts:get_sorted_nts_omit_section(hdrgo_prt={}, hdrgo_sort={})".format(
          #     hdrgo_prt, hdrgo_sort))
          hdrgos_seen = set()
          hdrgos_actual = self.sortgos.grprobj.get_hdrgos()
          for _, section_hdrgos_all in self.sections:
              #section_hdrgos_act = set(section_hdrgos_all).intersection(hdrgos_actual)
              section_hdrgos_act = [h for h in section_hdrgos_all if h in hdrgos_actual]
              hdrgos_seen |= set(section_hdrgos_act)
              self.sortgos.get_sorted_hdrgo2usrgos(
                  section_hdrgos_act, nts_flat, hdrgo_prt, hdrgo_sort)
          remaining_hdrgos = set(self.sortgos.grprobj.get_hdrgos()).difference(hdrgos_seen)
          self.sortgos.get_sorted_hdrgo2usrgos(remaining_hdrgos, nts_flat, hdrgo_prt, hdrgo_sort)
          return nts_flat
docs: Return a flat list of sections (wo/section names) with GO terms grouped and sorted.