### Question:
TreesImpl implements Trees { @Override public NodeStreamFactory nodeStreams() { return nodeStreamFactory; } 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 streams() { final Trees trees = Trees.get(); final NodeStreamFactory transformer = trees.nodeStreams(); assertTrue(transformer instanceof NodeStreamFactoryImpl); }