text: CAR_LIST = [
          {
              "serial": 123456,
              "color": "red",
              "year": 1999,
          },
          {
              "serial": 234567,
              "color": "black",
              "year": 2020,
          },
          {
              "serial": 345678,
              "color": "white",
              "year": 2012,
          },
      ]
  
  
  def filter_cars(car_list: list, year: int) -> list:
      """Filter cars by year."""
      result = []
      for car in car_list:
          if car["year"] < year:
              result.append(car)
      return result
  