Fix docker cleanup step ordering of BsonDiffVisitorIT.

Docker client was terminted before containers were.

Signed-off-by: Yufei Cai <yufei.cai@bosch.io>

internal/utils/test/src/test/java/org/eclipse/ditto/internal/utils/test/mongo/MongoDbResource.java

@@ -26,7 +26,7 @@
  * the MongoDB container address instead of starting its own container.
  */
 @NotThreadSafe
-public final class MongoDbResource extends ExternalResource implements Closeable {
+public final class MongoDbResource extends ExternalResource {
 
     private static final int MONGO_INTERNAL_PORT = 27017;
     private static final String MONGO_CONTAINER_ALREADY_STARTED = "Mongo container has already been started.";
@@ -62,11 +62,11 @@ protected void after() {
             mongoContainer.remove();
             mongoContainer = null;
         }
-    }
-
-    @Override
-    public void close() throws IOException {
-        mongoContainerFactory.close();
+        try {
+            mongoContainerFactory.close();
+        } catch (final IOException e) {
+            throw new AssertionError(e);
+        }
     }
 
     /**

thingsearch/service/src/test/java/org/eclipse/ditto/thingsearch/service/persistence/write/mapping/BsonDiffVisitorIT.java

@@ -62,11 +62,6 @@ public final class BsonDiffVisitorIT {
     private Policy policy;
     private Policy policy2;
 
-    @AfterClass
-    public static void closeMongoResource() throws IOException {
-        MONGO_RESOURCE.close();
-    }
-
     @Before
     public void init() {
         client = MongoClientWrapper.getBuilder()