@Override
  public boolean hasReferences() {
    // Grab the read lock here, because we need to ensure that: only when the atomic
    // replaceStoreFiles(..) finished, we can get all the complete store file list.
    this.storeEngine.readLock();
    try {
      // Merge the current store files with compacted files here due to HBASE-20940.
      Collection<HStoreFile> allStoreFiles = new ArrayList<>(getStorefiles());
      allStoreFiles.addAll(getCompactedFiles());
      return StoreUtils.hasReferences(allStoreFiles);
    } finally {
      this.storeEngine.readUnlock();
    }
  }
Call to complete a compaction. Its for the case where we find in the WAL a compaction that was
not finished. We could find one recovering a WAL after a regionserver crash. See HBASE-2231.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStore.java