### Question:
LienzoLayer { public boolean isReady() { return null != layer.getScene(); } LienzoLayer();   LienzoLayer(final LienzoCustomLayer layer); void setSkipDraw(final boolean skipDraw); LienzoLayer add(final IPrimitive<?> shape); LienzoLayer delete(final IPrimitive<?> shape); void clear(); void onAfterDraw(final Command callback); Layer getTopLayer(); void add(final Layer layer); boolean isReady(); void remove(final Layer layer); void destroy(); Layer getLienzoLayer(); org.kie.workbench.common.stunner.core.client.canvas.Transform getTransform(); void translate(final double tx,
                          final double ty); void scale(final double sx,
                      final double sy); void scale(final double delta);  }### Answer:
@Test public void testIsReady() { LienzoCustomLayer layer1 = mock(LienzoCustomLayer.class); LienzoLayer tested1 = new LienzoLayer(layer1); when(layer1.getScene()).thenReturn(scene); LienzoCustomLayer layer2 = mock(LienzoCustomLayer.class); LienzoLayer tested2 = new LienzoLayer(layer2); when(layer2.getScene()).thenReturn(null); assertTrue(tested1.isReady()); assertFalse(tested2.isReady()); }