Clean up for the Fix KafkaNull for JSONConverters

Fixes: #2924

Author: artembilan

spring-kafka/src/main/java/org/springframework/kafka/support/converter/ByteArrayJsonMessageConverter.java

@@ -31,6 +31,7 @@
  *
  * @author Gary Russell
  * @author Vladimir Loginov
+ *
  * @since 2.3
  *
  */
@@ -48,7 +49,7 @@ protected Object convertPayload(Message<?> message) {
 		try {
 			return message.getPayload() instanceof KafkaNull
 					? null
-					:  getObjectMapper().writeValueAsBytes(message.getPayload());
+					: getObjectMapper().writeValueAsBytes(message.getPayload());
 		}
 		catch (JsonProcessingException e) {
 			throw new ConversionException("Failed to convert to JSON", message, e);

spring-kafka/src/main/java/org/springframework/kafka/support/converter/BytesJsonMessageConverter.java

@@ -33,6 +33,7 @@
  *
  * @author Gary Russell
  * @author Vladimir Loginov
+ *
  * @since 2.1.7
  *
  */

spring-kafka/src/test/java/org/springframework/kafka/annotation/BatchListenerConversionTests.java

@@ -129,9 +129,13 @@ public void testBatchOfPojoMessages(@Autowired KafkaAdmin admin) throws Exceptio
 		assertThat(listener.received.size()).isGreaterThan(0);
 		assertThat(listener.received.get(0).getPayload()).isInstanceOf(Foo.class);
 		assertThat(listener.received.get(0).getPayload().getBar()).isEqualTo("bar");
-		assertThatNoException().isThrownBy(() -> this.template.send(
-				new GenericMessage<>(KafkaNull.INSTANCE, Collections.singletonMap(KafkaHeaders.TOPIC, topic))));
 		verify(admin, never()).clusterId();
+
+		assertThatNoException()
+				.isThrownBy(() ->
+						this.template.send(
+								new GenericMessage<>(KafkaNull.INSTANCE,
+										Collections.singletonMap(KafkaHeaders.TOPIC, topic))));
 	}
 
 	@Test