### Question:
FacesView extends AbstractUrlBasedView { @Override public void setUrl(String url) { Assert.hasLength(url, "URL must not be empty"); super.setUrl(url); } FacesView();  FacesView(String url);  FacesView(ViewArtifact viewArtifact); @Override void setUrl(String url); String getViewId(); ViewArtifact getViewArtifact();  }### Answer:
@Test public void shouldNotSetNullUrl() throws Exception { FacesView view = new FacesView(); this.thrown.expect(IllegalArgumentException.class); this.thrown.expectMessage("URL must not be empty"); view.setUrl(null); }