### Question:
GroupByTagsTreeBuilder extends GroupByDefaultTreeBuilder { @Override public String getGroupByName() { return "Tag"; }  @Override String getGroupByName(); @Override GroupCategorizer getGroupCategorizer();  }### Answer:
@Test public void testGetGroupByName() { GroupByTagsTreeBuilder builder = new GroupByTagsTreeBuilder(); assertEquals("Tag", builder.getGroupByName()); }