### Question:
AgnosticTreeView implements TreeView { @Override public void clear() { cascade.clear(); polygonPanel.clear(); polygonPanel.resetTransformation(); } AgnosticTreeView(PolygonPanel polygonPanel); @Override void addNodeInteractionListener(NodeInteractionListener listener); @Override void colorNode(String nodeId, RGBColor color); @Override void addCascadeLoadedListener(CascadeLoadedListener listener); @Override void setCanvasBackground(RGBColor color); @Override void loadCascade(Cascade newCascade, boolean resetView); @Override void addSpecialControl(String nodeId, SpecialControl specialControl); @Override void initNodeNames(); @Override void initToolTips(ToolTipProperties properties); @Override void loadNodeNamesFrom(NodePresentationProperties nodePresentationProperties); @Override void clear(); @Override void registerSpecialType(Class contentClass, ContentFactory factory);  }### Answer:
@Test public void isEmptyAfterClear() throws Exception { treeView.clear(); verify(panel).clear(); }
@Test public void resetsPanelDuringClear() throws Exception { treeView.clear(); verify(panel).resetTransformation(); }