### Question:
LocalClipboardControl extends AbstractCanvasControl<AbstractCanvas> implements ClipboardControl<Element, AbstractCanvas, ClientSession> { @Override public ClipboardControl<Element, AbstractCanvas, ClientSession> clear() { commands.clear(); elements.clear(); elementsParent.clear(); return this; } LocalClipboardControl(); @Override ClipboardControl<Element, AbstractCanvas, ClientSession> set(Element... element); @Override ClipboardControl<Element, AbstractCanvas, ClientSession> remove(Element... element); @Override Collection<Element> getElements(); @Override ClipboardControl<Element, AbstractCanvas, ClientSession> clear(); @Override boolean hasElements(); @Override String getParent(String uuid); @Override List<Command> getRollbackCommands(); @Override ClipboardControl<Element, AbstractCanvas, ClientSession> setRollbackCommand(Command... command); @Override Map<String, EdgeClipboard> getEdgeMap(); @Override EdgeClipboard buildNewEdgeClipboard(final String source, final Connection sourceConnection, final String target, final Connection targetConnection);  }### Answer:
@Test public void testClear() { localClipboardControl.set(graphInstance.startNode, graphInstance.intermNode, graphInstance.endNode); assertTrue(localClipboardControl.hasElements()); localClipboardControl.clear(); assertFalse(localClipboardControl.hasElements()); }