### Question:
RestAuthConfirmationCallbackHandler extends AbstractRestAuthCallbackHandler<ConfirmationCallback> { public ConfirmationCallback handle(HttpServletRequest request, HttpServletResponse response, JsonValue postBody, ConfirmationCallback originalCallback) { return originalCallback; }  ConfirmationCallback handle(HttpServletRequest request, HttpServletResponse response,
            JsonValue postBody, ConfirmationCallback originalCallback); String getCallbackClassName(); JsonValue convertToJson(ConfirmationCallback callback, int index); ConfirmationCallback convertFromJson(ConfirmationCallback callback, JsonValue jsonCallback);  }### Answer:
@Test public void shouldHandleCallback() { HttpServletRequest request = mock(HttpServletRequest.class); HttpServletResponse response = mock(HttpServletResponse.class); JsonValue jsonPostBody = mock(JsonValue.class); ConfirmationCallback originalConfirmationCallback = mock(ConfirmationCallback.class); ConfirmationCallback confirmationCallback = restAuthConfirmationCallbackHandler.handle(request, response, jsonPostBody, originalConfirmationCallback); assertEquals(originalConfirmationCallback, confirmationCallback); }