### Question:
SupportedClassifierDefinitionListener extends DataTreeChangeHandler<SupportedClassifierDefinition> { @VisibleForTesting List<ParameterName> getAllSupportedParams(final ClassifierDefinitionId cdId) { return FluentIterable.from(validatorByRendererAndCd.column(cdId).values()) .transformAndConcat(new Function<ClassifierInstanceValidator, Set<ParameterName>>() { @Override public Set<ParameterName> apply(ClassifierInstanceValidator input) { return input.getSupportedParameters(); } }) .toList(); } SupportedClassifierDefinitionListener(DataBroker dataProvider, PolicyValidatorRegistry validatorRegistry);   }### Answer:
@Test public void testGetAllSupportedParams() { List<SupportedParameterValues> srcPortParam = ImmutableList.of(new SupportedParameterValuesBuilder() .setParameterName(new ParameterName(L4ClassifierDefinition.SRC_PORT_PARAM)).build()); SupportedClassifierDefinition supportedL4SrcPort = new SupportedClassifierDefinitionBuilder() .setClassifierDefinitionId(L4ClassifierDefinition.ID).setSupportedParameterValues(srcPortParam).build(); RendererName rendererFoo = new RendererName("Foo"); listener.validatorByRendererAndCd.put(rendererFoo, supportedL4SrcPort.getClassifierDefinitionId(), new ClassifierInstanceValidator(supportedL4SrcPort, rendererFoo)); List<SupportedParameterValues> dstPortParam = ImmutableList.of(new SupportedParameterValuesBuilder() .setParameterName(new ParameterName(L4ClassifierDefinition.DST_PORT_PARAM)).build()); SupportedClassifierDefinition supportedL4DstPort = new SupportedClassifierDefinitionBuilder() .setClassifierDefinitionId(L4ClassifierDefinition.ID).setSupportedParameterValues(dstPortParam).build(); RendererName rendererBar = new RendererName("Bar"); listener.validatorByRendererAndCd.put(rendererBar, supportedL4DstPort.getClassifierDefinitionId(), new ClassifierInstanceValidator(supportedL4DstPort, rendererBar)); List<ParameterName> allSupportedParams = listener.getAllSupportedParams(L4ClassifierDefinition.ID); Assert.assertTrue(allSupportedParams.contains(new ParameterName(L4ClassifierDefinition.SRC_PORT_PARAM))); Assert.assertTrue(allSupportedParams.contains(new ParameterName(L4ClassifierDefinition.DST_PORT_PARAM))); }