public class Car extends CarTester
{
    private double milesDriven;
    private double gasTank;

    private double getGasInTank;
    private double getMilesDriven;
   /**
      Constructs a car with a given fuel efficiency.
      @param anEfficiency the fuel efficiency of the car
   */
   public Car(double anEfficiency)
   {
   }

   /** Adds gas to the teank.
       @param amount the amount of fuel to add
   */
   public void addGas(double amount)
   {
        gasTank = amount + amount + amount;

   }

   /**
       Drives a certain amount, consuming gas.
       @param distance the distance driven
   */
   public void drive(double distance)
   {
       milesDriven = distance + milesDriven;
   }

   /**
       Gets the amount of gas left in the tank.
       @return the amount of gas
   */
   public double getGasInTank()
   {
       getGasInTank = gasTank - (milesDriven/50);
       return getGasInTank;
    }

   /**
       Gets the total miles driven by this car.
       @return the miles driven
   */
   public double getMilesDriven()
   {
      return milesDriven;
   }
}