@Test
public void testUsernamesList() {

  Map<String, String> list = contributorsListProvider.getList(ContributorsListProvider.NAMES_TO_USERNAMES, null);
  Assert.assertTrue(list.containsKey(user1.getUsername()));
  Assert.assertTrue(list.containsKey(user2.getUsername()));
  Assert.assertTrue(list.containsKey(user3.getUsername()));
  Assert.assertTrue(list.containsValue(user1.getName()));
  Assert.assertTrue(list.containsValue(user2.getName()));
  Assert.assertTrue(list.containsValue(user3.getUsername()));
  Assert.assertTrue(list.containsKey("User 5"));
  Assert.assertTrue(list.containsValue("User 5"));
  Assert.assertEquals(5, list.size());
}