Close thread pool executor in observationShouldNotLeakToFutureCompletionThread test

Signed-off-by: Maksim Petelin <[email protected]>

Author: pema4

samples/micrometer-samples-spring-framework6/src/test/java/io/micrometer/samples/spring6/aop/ObservedAspectTests.java

@@ -178,15 +178,16 @@ void observationShouldNotLeakToFutureCompletionThread() {
 
         ObservedService service = pf.getProxy();
         FakeAsyncTask fakeAsyncTask = new FakeAsyncTask("test-result");
-        Executor sameThreadExecutor = new ThreadPoolExecutor(1, 1, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<>());
-        CompletableFuture<String> asyncResult = service
-            .parent(() -> service.asyncChild(fakeAsyncTask, sameThreadExecutor));
-        CompletableFuture<Void> asyncAssertion = asyncResult
-            .thenRunAsync(() -> assertThat(registry).doesNotHaveAnyRemainingCurrentObservation(), sameThreadExecutor);
-        fakeAsyncTask.proceed();
-        fakeAsyncTask.get();
 
-        assertThat(asyncAssertion).succeedsWithin(Duration.ofMillis(200));
+        try (var sameThreadExecutor = new ThreadPoolExecutor(1, 1, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<>())) {
+            CompletableFuture<String> asyncResult = service
+                .parent(() -> service.asyncChild(fakeAsyncTask, sameThreadExecutor));
+            CompletableFuture<Void> asyncAssertion = asyncResult.thenRunAsync(
+                    () -> assertThat(registry).doesNotHaveAnyRemainingCurrentObservation(), sameThreadExecutor);
+            fakeAsyncTask.proceed();
+
+            assertThat(asyncAssertion).succeedsWithin(Duration.ofMillis(200));
+        }
     }
 
     @Test