[NO ISSUE][STO] Enable extension of LSMBTreeIOOperationCallback.afterOperation

- user model changes: no
- storage format changes: no
- interface changes: no

Change-Id: I57f1d60b47ba3fb6748c84ef4b24866943a3e57d
Reviewed-on: https://asterix-gerrit.ics.uci.edu/2092
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Contrib: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Michael Blow <mblow@apache.org>
diff --git a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java
index ba0f928..3138986 100644
--- a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java
+++ b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java
@@ -181,7 +181,7 @@
     }
 
     @Override
-    public final void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents,
+    public void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents,
             ILSMDiskComponent newComponent) throws HyracksDataException {
         //TODO: Copying Filters and all content of the metadata pages for flush operation should be done here
         if (newComponent != null) {