### Question:
PayloadValidationExtensionPointHander extends ExtensionPointIteratedHandler { private void register(String cpaId, Class<? extends Validator> handlerClass, Properties config) { String contentType = config.getProperty("contentType"); ValidatorComponent vc = getComponent(); if(contentType == null) { vc.registerDefault(cpaId, handlerClass,config); } else { vc.register(cpaId, contentType, handlerClass,config); } }  @SuppressWarnings("unchecked") @Override void processExtension(Extension extension);  }### Answer:
@Test public void testRegisterExtensionPointWithContentType() throws Exception { Properties config = new Properties(); config.setProperty("class", "org.jentrata.validation.extension.PayloadValidationExtensionPointHanderTest.MockValidator"); config.setProperty("cpaId", "test"); config.setProperty("contentType", "text/plain"); assertRegisterExtensionPoint(config); verify(mockValidatorComponent).register(eq("test"), eq("text/plain"), eq(MockValidator.class),isA(Properties.class)); }