### Question:
RuleHandlerRegistryImpl implements RuleHandlerRegistry { @Override @SuppressWarnings("unchecked") public <T extends RuleExtensionHandler> T getExtensionHandler(final Class<T> contextType) { return (T) extensionHandlers.get(contextType); }  @Override void register(final RuleEvaluationHandler handler); @Override Collection<RuleEvaluationHandler> getHandlersByContext(final Class<?> contextType); @Override @SuppressWarnings("unchecked") T getExtensionHandler(final Class<T> contextType); @Override void clear(); @Override boolean isEmpty(); @Override boolean remove(final RuleEvaluationHandler item); @Override boolean contains(final RuleEvaluationHandler item);  }### Answer:
@Test @SuppressWarnings("unchecked") public void testGetExtension() { final RuleExtensionHandlerStub _extensionHandler = tested.getExtensionHandler(RuleExtensionHandlerStub.class); assertNotNull(_extensionHandler); assertEquals(extensionHandler, _extensionHandler); }