### Question:
GroupByActiveZOrderTreeBuilder extends GroupByDefaultTreeBuilder { @Override public String getGroupByName() { return "Z-Order"; }  @Override String getGroupByName(); @Override GroupCategorizer getGroupCategorizer(); @Override Comparator<? super DataGroupInfo> getGroupComparator(); @Override TreeOptions getTreeOptions(); @Override Comparator<? super DataTypeInfo> getTypeComparator();  }### Answer:
@Test public void testGetGroupByName() { GroupByActiveZOrderTreeBuilder builder = new GroupByActiveZOrderTreeBuilder(); assertEquals("Z-Order", builder.getGroupByName()); }