public void testGroupNamesEmpty() throws Exception
    {
        // Setup test fixture.
        final DefaultGroupProvider provider = new DefaultGroupProvider();

        // Execute system under test.
        final Collection<String> result = provider.getGroupNames();

        // Verify result.
        assertEquals(0, result.size());
    }
Verifies that a {@link DefaultGroupProvider#getGroupNames()} returns an empty collection when no groups
are present.
xmppserver/src/test/java/org/jivesoftware/openfire/group/DefaultGroupProviderTest.java