@Override
  public boolean containsKey(KeyInfo keyInfo, LocalRegion localRegion) {
    TXEntryState tx = txReadEntry(keyInfo, localRegion, true, true/* create txEntry is absent */);
    if (tx != null) {
      return tx.existsLocally();
    } else {
      return localRegion.nonTXContainsKey(keyInfo);
    }
  }
This form of txReadEntry takes a concurrent-map argument, expectedOldValue. If this parameter
is not null it must match the current value of the entry or an EntryNotFoundException is
thrown.
geode-core/src/main/java/org/apache/geode/internal/cache/TXState.java