@Override
  public Object getKeyForIterator(KeyInfo curr, LocalRegion currRgn, boolean rememberReads,
      boolean allowTombstones) {
    assert !(curr.getKey() instanceof RegionEntry);
    TXEntryState txEntryState =
        readEntryAndCheckIfDestroyed(curr, currRgn, rememberReads, allowTombstones);
    if (txEntryState != null) {
      // txEntry is created/read into txState.
      return curr.getKey();
    }
    return null;
  }
throws an exception when cloning is disabled while using delta
geode-core/src/main/java/org/apache/geode/internal/cache/TXState.java