### Question:
CanvasBoundsIndexerImpl implements CanvasBoundsIndexer<AbstractCanvasHandler> { @Override public void destroy() { this.canvasHandler = null; }  BoundsIndexer<AbstractCanvasHandler, Node<View<?>, Edge>> build(final AbstractCanvasHandler context); @Override @SuppressWarnings("unchecked") Node<View<?>, Edge> getAt(final double x,
                                     final double y); @Override @SuppressWarnings("unchecked") Node<View<?>, Edge> getAt(final double x,
                                     final double y,
                                     final double width,
                                     final double height,
                                     final Element parentNode); @Override double[] getTrimmedBounds(); @Override void destroy();  }### Answer:
@Test public void testDestroy() { canvasBoundsIndexerImpl.destroy(); assertNull(canvasBoundsIndexerImpl.canvasHandler); }