@Test public void testPostback() throws IOException { parse("callback/postback.json", callbackRequest -> { assertDestination(callbackRequest); assertThat(callbackRequest.getEvents()).hasSize(1); Event event = callbackRequest.getEvents().get(0); assertThat(event).isInstanceOf(PostbackEvent.class); assertThat(event.getSource()) .isInstanceOf(UserSource.class); assertThat(event.getSource().getUserId()) .isEqualTo("u206d25c2ea6bd87c17655609a1c37cb8"); assertThat(event.getTimestamp()) .isEqualTo(Instant.parse("2016-05-07T13:57:59.859Z")); PostbackEvent postbackEvent = (PostbackEvent) event; assertThat(postbackEvent.getPostbackContent().getData()) .isEqualTo("action=buyItem&itemId=123123&color=red"); }); }