GwtMockito: A widget that has an existing parent widget may not be added to the detach list

I try to test my view with GwtMockito and have this problem:

java.lang.AssertionError: A widget that has an existing parent widget may not be added to the detach list
    at com.google.gwt.user.client.ui.RootPanel.detachOnWindowClose(RootPanel.java:137)
    at com.google.gwt.user.client.ui.RootPanel.get(RootPanel.java:211)
    at com.google.gwt.user.client.ui.RootPanel.get(RootPanel.java:151)
    at com.ait.lienzo.client.core.shape.Node.<clinit>(Node.java:112)
    at sun.reflect.GeneratedSerializationConstructorAccessor17.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at org.objenesis.instantiator.sun.SunReflectionFactoryInstantiator.newInstance(SunReflectionFactoryInstantiator.java:40)
    at org.objenesis.ObjenesisBase.newInstance(ObjenesisBase.java:59)
    at org.mockito.internal.creation.jmock.ClassImposterizer.createProxy(ClassImposterizer.java:128)
    at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:63)
    at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:56)
    at org.mockito.internal.creation.CglibMockMaker.createMock(CglibMockMaker.java:23)
    at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:26)
    at org.mockito.internal.MockitoCore.mock(MockitoCore.java:51)
    at org.mockito.Mockito.mock(Mockito.java:1243)
    at org.mockito.Mockito.mock(Mockito.java:1216)
    at com.google.gwtmockito.GwtMockito$Bridge.create(GwtMockito.java:317)
    at com.google.gwt.core.shared.GWT.createImpl(GWT.java:83)
    at com.google.gwt.core.client.GWT.create(GWT.java:86)
    at online.draughts.rus.client.application.home.PlayComponentView.initEmptyDeskPanel(PlayComponentView.java:195)

I try to create LienzoPanel in PlayComponentView like this:

Layer initDeskRect = GWT.create(Layer.class);
Rectangle contour = GWT.create(Rectangle.class);
...
lienzoPanel = GWT.create(LienzoPanel.class);
lienzoPanel.setBackgroundLayer(initDeskRect);
...

I investigated that there is problem in Node.java:

static
{
    RootPanel.get().getElement().getStyle().setProperty("webkitTapHighlightColor", "rgba(0,0,0,0)");
}

Any idea how to resolve this?