DefaultExceptionToAcknowledgementConverter extends ExceptionToAcknowledgementConverter { static DefaultExceptionToAcknowledgementConverter getInstance() { DefaultExceptionToAcknowledgementConverter result = instance; if (null == result) { result = new DefaultExceptionToAcknowledgementConverter(); instance = result; } return result; } private  DefaultExceptionToAcknowledgementConverter();   }
@Test public void getInstanceCreatesSingleton() { final DefaultExceptionToAcknowledgementConverter firstInstance = DefaultExceptionToAcknowledgementConverter.getInstance(); final DefaultExceptionToAcknowledgementConverter secondInstance = DefaultExceptionToAcknowledgementConverter.getInstance(); assertThat(firstInstance).isSameAs(secondInstance); }