@Override
    public void handleNewUndeleteEntry(StoreKey key, IndexValue undeleteValue, IndexValue originalPutValue,
        IndexValue previousValue) {
      this.currentValue = undeleteValue;
      this.originalPutValue = originalPutValue;
      this.previousValue = previousValue;
    }
Replace initial index in store with mock index which would throw specified exception when finding entries/keys.
@param exception the store exception to throw when finding entries or missing keys.
@throws StoreException
ambry-store/src/test/java/com/github/ambry/store/BlobStoreTest.java