code: def PluRunOff_cowinners(self, profile):
          elecType = profile.getElecType()
          if elecType != "soc" and elecType != "toc" and elecType != "csv":
              print("ERROR: unsupported election type")
              exit()
          prefcounts = profile.getPreferenceCounts()
          len_prefcounts = len(prefcounts)
          rankmaps = profile.getRankMaps()
          ranking = MechanismPlurality().getRanking(profile)
          known_winners = set()
          top_2_combinations = []
          if len(ranking[0][0]) > 1:
              for cand1, cand2 in itertools.combinations(ranking[0][0], 2):
                  top_2_combinations.append([cand1, cand2])
          else:
              max_cand = ranking[0][0][0]
              if len(ranking[0][1]) > 1:
                  for second_max_cand in ranking[0][1]:
                      top_2_combinations.append([max_cand, second_max_cand])
              else:
                  second_max_cand = ranking[0][1][0]
                  top_2_combinations.append([max_cand, second_max_cand])
          for top_2 in top_2_combinations:
              dict_top2 = {top_2[0]: 0, top_2[1]: 0}
              for i in range(len_prefcounts):
                  vote_top2 = {key: value for key, value in rankmaps[i].items() if key in top_2}
                  top_position = min(vote_top2.values())
                  keys = [x for x in vote_top2.keys() if vote_top2[x] == top_position]
                  for key in keys:
                      dict_top2[key] += prefcounts[i]
              max_value = max(dict_top2.values())
              winners = [y for y in dict_top2.keys() if dict_top2[y] == max_value]
              known_winners = known_winners | set(winners)
          return sorted(known_winners)