public void extendAndImportGroup() throws Exception {
// group1 -> group2
group1.setParentGroup("group2");
// group2 imports group3.*
group2.setImports(createImportList(new ImportImpl("group3", null)));
// group3 imports group4.field4
group3.setImports(createImportList(new ImportImpl("group4", "field4")));
initForm(createGroupList(group1, group2, group3, group4));
assertFields(group1, "field1", "field2", "field3", "field4");
assertFields(group2, "field2", "field3", "field4");