@Test
public void testGetGroupItemSelectorProviderOptionalWithRegisteredGroupItemSelectorProvider() {

	ReflectionTestUtil.setFieldValue(
		GroupItemSelectorTrackerUtil.class, "_serviceTrackerMap",
		new MockServiceTrackerMap(
			Collections.singletonMap(
				"test", new MockGroupItemSelectorProvider())));
	Optional<GroupItemSelectorProvider> groupItemSelectorProviderOptional =
		GroupItemSelectorTrackerUtil.getGroupItemSelectorProviderOptional(
			"test");
	Assert.assertTrue(groupItemSelectorProviderOptional.isPresent());
	GroupItemSelectorProvider groupItemSelectorProvider =
		groupItemSelectorProviderOptional.get();
	Assert.assertEquals("icon", groupItemSelectorProvider.getIcon());
	ReflectionTestUtil.setFieldValue(
		GroupItemSelectorTrackerUtil.class, "_serviceTrackerMap", null);
}