MetaImpl implements Meta<A, B> { @Override public String toString() { return "MetaImpl{" + "model=" + model + ", result=" + result + ", transform=" + transform + ", factory=" + factory + ", stack=" + stack + ", tree=" + tree + '}'; } private  MetaImpl(
            A model, 
            B result, 
            Transform<A, B> transform, 
            TransformFactory factory, 
            RenderStack stack, 
            RenderTree tree); @Override B getResult(); @Override Transform<A, B> getTransform(); @Override TransformFactory getFactory(); @Override A getModel(); @Override RenderStack getRenderStack(); @Override RenderTree getRenderTree(); @Override String toString();  }
@Test void testToString() { final String s = instance.toString(); assertTrue(s.contains("model")); assertTrue(s.contains("result")); assertTrue(s.contains("1")); }