@Override
    public SfmSketchState createSingleState()
    {
        return new SingleSfmSketchState();
    }
@Test
    public void testCreateSingleStateEmpty()
    {
        SfmSketchState state = factory.createSingleState();
        assertNull(state.getSketch());
        assertEquals(state.getEstimatedSize(), ClassLayout.parseClass(SfmSketchStateFactory.SingleSfmSketchState.class).instanceSize());
    }