input: Write a python function to check if the car stays within the screen boundaries.
  assert car_within_boundaries(0, 0, 700, 500, Car()) == True
  assert car_within_boundaries(350, 400, 700, 500, Car()) == True
  assert car_within_boundaries(701, 400, 700, 500, Car()) == False
output: def car_within_boundaries(car_x, car_y, screen_width, screen_height, car):
      if car_x < 0 or car_x > screen_width or car_y < 0 or car_y > screen_height:
          return False
      return True
  
  class Car:
      pass