Adding default.

amazon-kinesis-client/src/main/java/software/amazon/kinesis/retrieval/RecordsPublisher.java

@@ -68,14 +68,18 @@ public interface RecordsPublisher extends Publisher<RecordsRetrieved> {
      *
      * @return requestId associated with last succesful response.
      */
-    String getLastSuccessfulResponseRequestId();
+    default String getLastSuccessfulResponseRequestId() {
+        return getLastSuccessfulResponseDetails().map(RequestDetails::requestId).orElse(NONE);
+    }
 
     /**
      * Gets last successful response's timestamp.
      *
      * @return timestamp associated with last successful response.
      */
-    String getLastSuccessfulResponseTimestamp();
+    default String getLastSuccessfulResponseTimestamp() {
+        return getLastSuccessfulResponseDetails().map(RequestDetails::timestamp).orElse(NONE);
+    }
 
     /**
      * Notify the publisher on receipt of a data event.

amazon-kinesis-client/src/main/java/software/amazon/kinesis/retrieval/fanout/FanOutRecordsPublisher.java

@@ -156,16 +156,6 @@ public class FanOutRecordsPublisher implements RecordsPublisher {
         lastSuccessfulRequestDetails = Optional.of(requestDetails);
     }
 
-    @Override
-    public String getLastSuccessfulResponseRequestId() {
-        return getLastSuccessfulResponseDetails().map(RequestDetails::requestId).orElse(NONE);
-    }
-
-    @Override
-    public String getLastSuccessfulResponseTimestamp() {
-        return getLastSuccessfulResponseDetails().map(RequestDetails::timestamp).orElse(NONE);
-    }
-
     // This method is not thread-safe. You need to acquire a lock in the caller in order to execute this.
     @VisibleForTesting
     RecordFlow evictAckedEventAndScheduleNextEvent(RecordsDeliveryAck recordsDeliveryAck) {

amazon-kinesis-client/src/main/java/software/amazon/kinesis/retrieval/polling/BlockingRecordsPublisher.java

@@ -77,16 +77,6 @@ public class BlockingRecordsPublisher implements RecordsPublisher {
         return Optional.empty();
     }
 
-    @Override
-    public String getLastSuccessfulResponseRequestId() {
-        return NONE;
-    }
-
-    @Override
-    public String getLastSuccessfulResponseTimestamp() {
-        return NONE;
-    }
-
     @Override
     public void subscribe(Subscriber<? super RecordsRetrieved> s) {
         subscriber = s;

amazon-kinesis-client/src/main/java/software/amazon/kinesis/retrieval/polling/PrefetchRecordsPublisher.java

@@ -267,16 +267,6 @@ public class PrefetchRecordsPublisher implements RecordsPublisher {
         return Optional.empty();
     }
 
-    @Override
-    public String getLastSuccessfulResponseRequestId() {
-        return NONE;
-    }
-
-    @Override
-    public String getLastSuccessfulResponseTimestamp() {
-        return NONE;
-    }
-
     @Override
     public void restartFrom(RecordsRetrieved recordsRetrieved) {
         if (!(recordsRetrieved instanceof PrefetchRecordsRetrieved)) {

amazon-kinesis-client/src/test/java/software/amazon/kinesis/lifecycle/ShardConsumerSubscriberTest.java

@@ -563,16 +563,6 @@ public class ShardConsumerSubscriberTest {
             return Optional.empty();
         }
 
-        @Override
-        public String getLastSuccessfulResponseRequestId() {
-            return NONE;
-        }
-
-        @Override
-        public String getLastSuccessfulResponseTimestamp() {
-            return NONE;
-        }
-
         @Override
         public void subscribe(Subscriber<? super RecordsRetrieved> s) {
             subscriber = s;

amazon-kinesis-client/src/test/java/software/amazon/kinesis/lifecycle/ShardConsumerTest.java

@@ -215,16 +215,6 @@ public class ShardConsumerTest {
             return Optional.empty();
         }
 
-        @Override
-        public String getLastSuccessfulResponseRequestId() {
-            return NONE;
-        }
-
-        @Override
-        public String getLastSuccessfulResponseTimestamp() {
-            return NONE;
-        }
-
         @Override
         public void subscribe(Subscriber<? super RecordsRetrieved> s) {
             subscriber = s;