@Override
  public Iterator<HStoreFile> getCandidateFilesForRowKeyBefore(final KeyValue targetKey) {
    KeyBeforeConcatenatedLists result = new KeyBeforeConcatenatedLists();
    // Order matters for this call.
    result.addSublist(state.level0Files);
    if (!state.stripeFiles.isEmpty()) {
      int lastStripeIndex = findStripeForRow(CellUtil.cloneRow(targetKey), false);
      for (int stripeIndex = lastStripeIndex; stripeIndex >= 0; --stripeIndex) {
        result.addSublist(state.stripeFiles.get(stripeIndex));
      }
    }
    return result.iterator();
  }
See {@link StoreFileManager#getCandidateFilesForRowKeyBefore(KeyValue)} for details on this
methods.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StripeStoreFileManager.java