diff --git a/sources/tech/20211102 Apache Kafka- Asynchronous Messaging for Seamless Systems.md b/sources/tech/20211102 Apache Kafka- Asynchronous Messaging for Seamless Systems.md
index 8646536175..958d99e847 100644
--- a/sources/tech/20211102 Apache Kafka- Asynchronous Messaging for Seamless Systems.md	
+++ b/sources/tech/20211102 Apache Kafka- Asynchronous Messaging for Seamless Systems.md	
@@ -169,36 +169,36 @@ The Fleet class simulates the Kafka producer applications running on six buses o
 
 ```
 public class Fleet {
-	public static void main(String[] args) throws Exception {
-		String broker = “localhost:9092”;
-		Properties props = new Properties();
-		props.setProperty(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, broker);
-		props.setProperty(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG,
-			StringSerializer.class.getName());
-		props.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,
-			StringSerializer.class.getName());
+    public static void main(String[] args) throws Exception {
+        String broker = “localhost:9092”;
+        Properties props = new Properties();
+        props.setProperty(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, broker);
+        props.setProperty(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG,
+            StringSerializer.class.getName());
+        props.setProperty(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,
+            StringSerializer.class.getName());
 
-		Producer<String, String> producer = new KafkaProducer<String, String>(props);
-		String topic = “abc-bus-location”;
-		Map<String, String> locations = new HashMap<>();
-		locations.put(“BLRHBL001”, “13.071362, 77.461906”);
-		locations.put(“BLRHBL002”, “14.399654, 76.045834”);
-		locations.put(“BLRHBL003”, “15.183959, 75.137622”);
-		locations.put(“BLRHBL004”, “13.659576, 76.944675”);
-		locations.put(“BLRHBL005”, “12.981337, 77.596181”);
-		locations.put(“BLRHBL006”, “13.024843, 77.546983”);
+        Producer<String, String> producer = new KafkaProducer<String, String>(props);
+        String topic = “abc-bus-location”;
+        Map<String, String> locations = new HashMap<>();
+        locations.put(“BLRHBL001”, “13.071362, 77.461906”);
+        locations.put(“BLRHBL002”, “14.399654, 76.045834”);
+        locations.put(“BLRHBL003”, “15.183959, 75.137622”);
+        locations.put(“BLRHBL004”, “13.659576, 76.944675”);
+        locations.put(“BLRHBL005”, “12.981337, 77.596181”);
+        locations.put(“BLRHBL006”, “13.024843, 77.546983”);
 
-		IntStream.range(0, 10).forEach(i -> {
-			for (String trip : locations.keySet()) {
-				ProducerRecord<String, String> record
-					= new ProducerRecord<String, String>(
-						topic, trip, locations.get(trip));
-				producer.send(record);
-			}
-		});
-		producer.flush();
-		producer.close();
-	}
+        IntStream.range(0, 10).forEach(i -> {
+            for (String trip : locations.keySet()) {
+                ProducerRecord<String, String> record
+                    = new ProducerRecord<String, String>(
+                        topic, trip, locations.get(trip));
+                producer.send(record);
+            }
+        });
+        producer.flush();
+        producer.close();
+    }
 }
 ```
 
@@ -208,34 +208,33 @@ The Dashboard class implements the Kafka consumer application and it runs at the
 
 ```
 public static void main(String[] args) {
-		String broker = “127.0.0.1:9092”;
-		String groupId = “abc-dashboard”;
-		Properties props = new Properties();
-		props.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, broker);
-		props.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
-			StringDeserializer.class.getName());
-		props.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
-			StringDeserializer.class.getName());
-		props.setProperty(ConsumerConfig.GROUP_ID_CONFIG, groupId);
+    String broker = “127.0.0.1:9092”;
+    String groupId = “abc-dashboard”;
+    Properties props = new Properties();
+    props.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, broker);
+    props.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG,
+        StringDeserializer.class.getName());
+    props.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,
+        StringDeserializer.class.getName());
+    props.setProperty(ConsumerConfig.GROUP_ID_CONFIG, groupId);
 
-		@SuppressWarnings(“resource”)
-		Consumer<String, String> consumer = new KafkaConsumer<String, String>(props);
-		consumer.subscribe(Arrays.asList(“abc-bus-location”));
-		while (true) {
-			ConsumerRecords<String, String> records
-				= consumer.poll(Duration.ofMillis(1000));
+    @SuppressWarnings(“resource”)
+    Consumer<String, String> consumer = new KafkaConsumer<String, String>(props);
+    consumer.subscribe(Arrays.asList(“abc-bus-location”));
+    while (true) {
+        ConsumerRecords<String, String> records
+            = consumer.poll(Duration.ofMillis(1000));
 
-			for (ConsumerRecord<String, String> record : records) {
-				String topic = record.topic();
-				int partition = record.partition();
-				String key = record.key();
-				String value = record.value();
-				System.out.println(String.format(
-					“Topic=%s, Partition=%d, Key=%s, Value=%s”,
-					topic, partition, key, value));
-			}
-		}
-	}
+        for (ConsumerRecord<String, String> record : records) {
+            String topic = record.topic();
+            int partition = record.partition();
+            String key = record.key();
+            String value = record.value();
+            System.out.println(String.format(
+                “Topic=%s, Partition=%d, Key=%s, Value=%s”,
+                topic, partition, key, value));
+        }
+    }
 }
 ```
 
@@ -245,14 +244,14 @@ A JDK of 8+ version is required to compile and run this code. The following Mave
 
 ```
 <dependency>
-	<groupId>org.apache.kafka</groupId>
-	<artifactId>kafka-clients</artifactId>
-	<version>2.8.0</version>
+  <groupId>org.apache.kafka</groupId>
+  <artifactId>kafka-clients</artifactId>
+  <version>2.8.0</version>
 </dependency>
 <dependency>
-	<groupId>org.slf4j</groupId>
-	<artifactId>slf4j-simple</artifactId>
-	<version>1.7.25</version>
+  <groupId>org.slf4j</groupId>
+  <artifactId>slf4j-simple</artifactId>
+  <version>1.7.25</version>
 </dependency>
 ```