@Test
 @Ignore
 public void testMeanNonStationary() {

     SarimaSpecification spec = new SarimaSpecification(12);
     spec.airline();
     SarimaModel arima = new SarimaModel(spec);
     arima.setBTheta(1, -.9);
     arima.setTheta(1, -.6);
     ArimaModelBuilder builder = new ArimaModelBuilder();
       builder.setDistribution(new T());
     double[] x = builder.generate(arima, 0.05, 300);
     GlsSarimaMonitor monitor = new GlsSarimaMonitor(null);
     RegArimaModel reg = new RegArimaModel(arima, new DataBlock(x));
     reg.setMeanCorrection(true);
     RegArimaEstimation rslt = monitor.optimize(reg);
     System.out.println(rslt.model.getArima().getMA());
     System.out.println(rslt.likelihood.getB()[0]);
      for (int i = 0; i < x.length; ++i) {
         System.out.println(x[i]);
     }
}