test : add test

Signed-off-by: Su Ko <rhtn1128@gmail.com>

Author: bandalgomsu

spring-kafka/src/test/java/org/springframework/kafka/listener/TransactionalContainerTests.java

@@ -1401,7 +1401,7 @@ void testFixTxOffsetsRetainsLeaderEpoch() throws Exception {
 		});
 
 		assertThat(latch.await(30, TimeUnit.SECONDS)).isTrue();
-		assertThat(committed.get().leaderEpoch()).isNotNull();
+		assertThat(committed.get().leaderEpoch().isPresent()).isTrue();
 		container.stop();
 	}