func_code: def swap_unique_keys_values(d):
      A = False
      kv = []
      values = []
      dic = {}
      new_values = []
      new_keys = []
      seen = {}
      for k, v in list(d.items()):
          kv.append((v, k))
      seen[kv[0][0]] = A
      for t in kv:
          if t[0] not in seen:
              seen[t[0]] = A
          else:
              seen[t[0]] = True
      for t in kv:
          if not seen[t[0]]:
              dic[t[0]] = t[1]
      return dic