@Test()
    public void testGetNonExistingGroup() throws Exception
    {
        // Setup test fixture.
        JiveGlobals.setProperty(MappedGroupProvider.PROPERTY_MAPPER_CLASSNAME, TestGroupProviderMapper.class.getName());
        final MappedGroupProvider provider = new MappedGroupProvider();

        // Execute system under test & Verify results.
        assertThrows(GroupNotFoundException.class, () -> provider.getGroup("non-existing-group"));
    }
Verifies that an exception is thrown when a non-existing group is being requested.
xmppserver/src/test/java/org/jivesoftware/openfire/group/MappedGroupProviderTest.java