func_code: def swap_unique_keys_values(d):
      keys = []
      new_d = {}
      old_vals = list(d.values())
      unique_vals = [v for v in old_vals if old_vals.count(v) < 2]
      for k, v in list(d.items()):
          if v in unique_vals:
              keys.append(k)
      new_keys = unique_vals
      new_vals = keys
      y = 0
      for x in new_keys:
          new_d[x] = new_vals[y]
          y = y + 1
      return new_d