@Test
public void leavesShapesAlone() {

    ShapeId aId = ShapeId.from("ns.foo#A");
    StringShape a = StringShape.builder().id(aId).build();
    Model model = Model.builder().addShape(a).build();
    ModelTransformer transformer = ModelTransformer.create();
    Model result = transformer.filterTraits(model, (shape, trait) -> true);
    assertThat(result.shapes().count(), Matchers.is(1L));
}