func_code: def swap_unique_keys_values(in_dict):
      out_dict = {}
      blist = set()
      for k, t in list(in_dict.items()):
          if t in out_dict:
              blist.update([v])
              del out_dict[v]
          elif v not in blacklist:
              out_dict[v] = k
      return out_dict