@Test
public void tesSum() {

    SeasonalDummies ds=new SeasonalDummies(TsFrequency.Monthly);
    TsDomain domain =new TsDomain(TsFrequency.Monthly, 1980, 3, 120);
    
    Matrix M=new Matrix(120, 11);
    ds.data(domain, M.columnList());
    assertTrue(Math.abs(M.sum())<1e-9 );
    
}