WebComponentConfigurationRegistry implements Serializable { public boolean hasConfigurations() { lock(); try { return configurationMap.size() > 0; } finally { unlock(); } } protected  WebComponentConfigurationRegistry(); Optional<WebComponentConfiguration<? extends Component>> getConfiguration(
            String tag); @SuppressWarnings("unchecked") Set<WebComponentConfiguration<T>> getConfigurationsByComponentType(
            Class<T> componentClass); boolean setConfigurations(
            Set<WebComponentConfiguration<? extends Component>> configurations); boolean hasConfigurations(); Optional<T> getEmbeddedApplicationAnnotation(
            Class<T> type); Set<WebComponentConfiguration<? extends Component>> getConfigurations(); void setShadowDomElements(List<Element> elements); List<Element> getShadowDomElements(); static WebComponentConfigurationRegistry getInstance(
            VaadinContext context);  }
@Test public void hasConfigurations() { registry.setConfigurations( createConfigurations(MyComponentExporter.class, MyComponentExporter2.class, UserBoxExporter.class)); Assert.assertTrue("Should have configurations, when 3 were set", registry.hasConfigurations()); }