### Question:
TreesImpl implements Trees { @Override public TreeBuilderFactory treeBuilders() { return treeBuilderFactory; } TreesImpl(); @Override TreeSelectorFactory treeSelectors(); @Override NodeSelectorFactory nodeSelectors(); @Override TreeWalkerFactory treeWalkers(); @Override TreeIteratorFactory treeIterators(); @Override NodeStreamFactory nodeStreams(); @Override TreeBuilderFactory treeBuilders(); @Override TreeTransformer transformations(); @Override Querier querier(); @Override SimpleCollection<Class<?>> availableTreeImplementations();  }### Answer:
@Test public void builders() { final Trees trees = Trees.get(); final TreeBuilderFactory transformer = trees.treeBuilders(); assertTrue(transformer instanceof TreeBuilderFactoryImpl); }