public class CarTest {
  public static void main(String[] args) {
    Car car1 = new Car(10.0, 20.0);
    double gas;
    gas = car1.getGas();
    System.out.println("The tank has " + gas + " gallons of gas.");
    car1.drive(100);
    gas = car1.getGas();
    System.out.println("The tank has " + gas + " gallons of gas.");
    car1.addGas(7);
    gas = car1.getGas();
    System.out.println("The tank has " + gas + " gallons of gas.");
  }
}