Checkstyle and jdk11 fix with spock

tests/samples-messaging-integration/src/main/java/com/example/BookService.java

@@ -36,7 +36,7 @@ public class BookService {
 	 * a possibility to "trigger" sending of a message to the given messageFrom server
 	 * side: will run the method and await upon receiving message on the output
 	 * messageFrom
-	 * 
+	 *
 	 * Method triggers sending a message to a source
 	 */
 	public void returnBook(BookReturned bookReturned) {
@@ -44,4 +44,5 @@ public class BookService {
 		this.outputChannel.send(MessageBuilder.withPayload(bookReturned)
 				.setHeader("BOOK-NAME", bookReturned.bookName).build());
 	}
+
 }