@Test
void identPrefix() {

    // following is not really useful
    IdentHelper identHelper = new IdentHelper();
    assertEquals(IdentHelper.identPrefix(-1),"");
    assertEquals(IdentHelper.identPrefix(0),"");
    assertEquals(IdentHelper.identPrefix(1),"  ");
    assertEquals(IdentHelper.identPrefix(2),"    ");
    assertEquals(IdentHelper.identPrefix(10),"                    ");
    assertEquals(IdentHelper.identPrefix(11),"                      ");
    assertEquals(IdentHelper.identPrefix(12),"                        ");
    assertEquals(IdentHelper.identPrefix(13),"                          ");
    assertEquals(IdentHelper.identPrefix(14),"                            ");
    assertEquals(IdentHelper.identPrefix(20),"                                        ");
}