### Question:
RestAuthX509CallbackHandler extends AbstractRestAuthCallbackHandler<X509CertificateCallback> { public X509CertificateCallback handle(HttpServletRequest request, HttpServletResponse response, JsonValue postBody, X509CertificateCallback originalCallback) { return originalCallback; }  boolean updateCallbackFromRequest(HttpServletRequest request,
            HttpServletResponse response, X509CertificateCallback callback); X509CertificateCallback handle(HttpServletRequest request, HttpServletResponse response,
            JsonValue postBody, X509CertificateCallback originalCallback); String getCallbackClassName(); JsonValue convertToJson(X509CertificateCallback callback, int index); X509CertificateCallback convertFromJson(X509CertificateCallback callback, JsonValue jsonCallback);  }### Answer:
@Test public void shouldHandleCallback() { HttpServletRequest request = mock(HttpServletRequest.class); HttpServletResponse response = mock(HttpServletResponse.class); JsonValue jsonPostBody = mock(JsonValue.class); X509CertificateCallback originalX509CertificateCallback = mock(X509CertificateCallback.class); X509CertificateCallback x509CertificateCallback = restAuthX509CallbackHandler.handle(request, response, jsonPostBody, originalX509CertificateCallback); Assert.assertEquals(originalX509CertificateCallback, x509CertificateCallback); }