### Question:
HoltWintersComputer { public double getAlpha() { return alpha; } HoltWintersComputer(final double alpha);  HoltWintersComputer(final double alpha, final double beta);  HoltWintersComputer(final double alpha, final double beta, final double gamma, final int period); void addNextValue(final double value); double getDeviation(); double getForecast(final int h); @Override String toString(); double getAlpha(); double getBeta(); double getGamma(); double[] getSeasonal();  }### Answer:
@Test(groups = "fast") public void testSimpleExponentialSmoothing() throws Exception { final double[] series = {315.42, 316.31, 316.50, 317.56, 318.13, 318.00, 316.39, 314.65, 313.68, 313.18, 314.66, 315.43}; final double[] smooth = {315.4200, 316.1320, 316.4264, 317.3333, 317.9707, 317.9941, 316.7108, 315.0622, 313.9564, 313.3353, 314.3951, 315.223}; final HoltWintersComputer computer = new HoltWintersComputer(0.8); Assert.assertEquals(computer.getAlpha(), 0.8); compare(computer, series, smooth, 0); }