public class Mower {

    // "fields", "instance variables", "attributes"
    private final String model;
    
    private double gasLevel;

    // Constructor - it is this method's responsibilty to
    // make sure that all instance variables have appropriate
    // values when the object is created.
    public Mower(String m, double g) {
        this.model = m;
        this.gasLevel = g;
    }

    public String getModel() {
        return this.model;
    }

    public double getGasLevel() {
        return this.gasLevel;
    }

    public void setGasLevel(double newGasLevel) {
        this.gasLevel = newGasLevel;
    }

    public void mow() {

        if (this.gasLevel > 0) {
            System.out.println("MOW MOW MOW, I'M MOWING!");
            this.gasLevel -= .5;
        } else {
            System.out.println("GLUB GLUB GLUB.  NO GAS!");
        }

        if (this.gasLevel < 0) {
            this.gasLevel = 0;
        }

    }

}