@Test
  public void testLinkWithNoComponentField() throws Exception {
    Component component = Component.create(NAMENODE,
        ImmutableList.of(Filter.linkNameFilter(NAMENODE_UI, true)));

    Service service = Service.create(HDFS, ImmutableList.of(), ImmutableList.of(component));

    QuickLinksProfile profile = QuickLinksProfile.create(ImmutableList.of(), ImmutableList.of(service));
    DefaultQuickLinkVisibilityController evaluator = new DefaultQuickLinkVisibilityController(profile);
    namenodeUi.setComponentName(null);
    assertFalse("Link should be hidden as there are no applicable filters", evaluator.isVisible(HDFS, namenodeUi));
  }
Test to prove that {@link Link}'s with unset {@code componentName} fields are handled properly.
ambari-server/src/test/java/org/apache/ambari/server/state/quicklinksprofile/QuickLinkVisibilityControllerTest.java