### Question:
InPlaceLeftRotator implements Rotator<E, MutableBinaryTreeNode<E>> { @Override public RotationDirection forDirection() { return RotationDirection.LEFT; }  @Override void rotate(ParentReference<MutableBinaryTreeNode<E>> reference, MutableBinaryTreeNode<E> currentRoot); @Override RotationDirection forDirection(); @Override Class<?> forClass();  }### Answer:
@Test public void forDirection() { final InPlaceLeftRotator<String> rotator = new InPlaceLeftRotator<>(); assertEquals(RotationDirection.LEFT, rotator.forDirection()); }