func_code: def seen(k, v):
      global skip
      if v in skip:
          return k, v
      else:
          return v, k
  
  
  def swap_unique_keys_values(d):
      global skip
      check = []
      for x in list(d.keys()):
          if d[x] not in check:
              check.append(d[x])
          else:
              skip.append(d[x])
      d = [seen(k, v) for k, v in list(d.items())]
      print(d)