### Question:
CategoryAxis3D extends CategoryAxis implements Cloneable, Serializable { @Override public Object clone() throws CloneNotSupportedException { return super.clone(); } CategoryAxis3D();  CategoryAxis3D(String label); @Override AxisState draw(Graphics2D g2,
                          double cursor,
                          Rectangle2D plotArea,
                          Rectangle2D dataArea,
                          RectangleEdge edge,
                          PlotRenderingInfo plotState); @Override double getCategoryJava2DCoordinate(CategoryAnchor anchor,
                                              int category,
                                              int categoryCount,
                                              Rectangle2D area,
                                              RectangleEdge edge); @Override Object clone();  }### Answer:
@Test public void testCloning() throws CloneNotSupportedException { CategoryAxis3D a1 = new CategoryAxis3D("Test"); CategoryAxis3D a2 = (CategoryAxis3D) a1.clone(); assertNotSame(a1, a2); assertSame(a1.getClass(), a2.getClass()); assertEquals(a1, a2); }