### Question:
TreesImpl implements Trees { @Override public TreeTransformer transformations() { return transformations; } 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 transformations() { final Trees trees = Trees.get(); final TreeTransformer transformer = trees.transformations(); assertTrue(transformer instanceof TreeTransformerImpl); }