func_code: def swap_unique_keys_values(dict_descriptor):
      new_dict = {}
      addthosevalues = set()
      for keys, values in list(dict_descriptor.items()):
          if values in new_dict:
              addthosevalues.update([values])
              del new_dict[values]
          elif values not in new_dict:
              new_dict[values] = keys
      return new_dict