LOG.debug("addChildGroup.12 " + extn);
  protected static Group addChildGroup(Stem ns, String extn, String displayExtn) {    try {      Group child = ns.addChildGroup(extn, displayExtn);      Assert.assertNotNull("child !null", child);      Assert.assertTrue("added child group", true);      Assert.assertTrue(        "child group instanceof Group",         child instanceof Group      );      Assert.assertNotNull("child uuid !null", child.getUuid());      Assert.assertTrue("child has uuid", !child.getUuid().equals(""));      Assert.assertTrue(        "parent stem", child.getParentStem().equals(ns)      );      Assert.assertTrue(        "group extension", child.getExtension().equals(extn)      );      Assert.assertTrue(        "group name", child.getName().equals(ns.getName() + ":" + extn)      );      Assert.assertTrue(        "group displayExtension",         child.getDisplayExtension().equals(displayExtn)      );      Assert.assertTrue(        "group displayName",         child.getDisplayName().equals(ns.getDisplayName() + ":" + displayExtn)      );      return child;    }    catch (Exception e) {      Assert.fail("failed to add group: " + e.getMessage());    }    throw new RuntimeException(Helper.ERROR);  } // protected static Group addChildGroup(ns, extn, displayExtn)