public void testExcludeFilter() throws Exception {
PluginFilterRetriever fb = new PluginFilterRetriever();
PluginFilter bean = fb.getPluginFilter(null, " three , four ");
assertTrue(bean instanceof ExcludingPluginFilter);
ExcludingPluginFilter filter = (ExcludingPluginFilter)bean;
Set suppliedNames = filter.getSuppliedNames();
assertEquals(2, suppliedNames.size());
assertTrue(suppliedNames.contains("four"));
}