@Test
public void testGetGroupMappingsWithEmptyProperty() throws Exception
{

    this.mockery.checking(new Expectations()
    {{
        allowing(xwikiMock).getXWikiPreference("puma_groupsMapping", getContext()); will(returnValue(""));
        allowing(xwikiMock).Param("xwiki.authentication.puma.groupsMapping"); will(returnValue(""));
    }});
    Map<String, Collection<String>> groupMapping = this.config.getGroupMapping(getContext());
    Assert.assertTrue(groupMapping.isEmpty());
}