### Question:
BasicTreeNodeFactory extends AbstractTreeNodeFactory { @Override public TreeNode getRootNode() { return new RootNode(); } BasicTreeNodeFactory(); @Override TreeNode getRootNode();  }### Answer:
@Test public void retrieveRootNode() { TreeNode rootNode = factory.getRootNode(); assertNotNull(rootNode); assertTrue(rootNode.isRoot()); assertFalse(rootNode.isWildcard()); }