@Before
    public void setUp() {
        this._instance = new ChristmasDay();
        this._years = new LinkedList<Integer>();
        for (int year = 1974; year < 2021; year++)
            this._years.add(year);
        this._christmasDayUnitedStates = new HashMap<Integer, GregorianCalendar>();
        for (int year : this._years) {
            GregorianCalendar christmasDayUnitedStates = new GregorianCalendar(year, 11, 25);
            switch (year){
                case 1977:
                case 1983:
                case 1988:
                case 1994:
                case 2005:
                case 2011:
                case 2016:
                    christmasDayUnitedStates.add(GregorianCalendar.DATE, 1);
            }
            this._christmasDayUnitedStates.put(year, christmasDayUnitedStates);
        }
    }