func_code: def swap_unique_keys_values(s):
      new_dict = {}
      c = Counter(list(s.values()))
      l = [k for k, v in list(s.items()) if c[v] < 2]
      for key, value in list(s.items()):
          if s[key] in l:
              new_dict[value] = key
      return new_dict