@Test
@SuppressWarnings({ "unchecked", "rawtypes" })
public void exchangeGetCallbackWithLambdas() throws Exception {
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("MyHeader", "MyValue");
HttpEntity<?> requestEntity = new HttpEntity(requestHeaders);
ListenableFuture<ResponseEntity<String>> responseFuture =
template.exchange(baseUrl + "/{method}", HttpMethod.GET, requestEntity, String.class, "get");
responseFuture.addCallback(result -> assertEquals("Invalid content", helloWorld,
result.getBody()), ex -> fail(ex.getMessage()));
while (!responseFuture.isDone()) {