@VisibleForTesting
  public Set testHookTXKeys() {
    if (!isTX()) {
      throw new IllegalStateException(
          "tx not in progress");
    }
    TXStateProxyImpl tx = (TXStateProxyImpl) getTXState();
    if (!tx.isRealDealLocal()) {
      return Collections.emptySet();
    }
    TXRegionState txr = txReadRegion();
    if (txr == null) {
      return Collections.emptySet();
    }
    return txr.getEntryKeys();
  }
This is a test hook method used to find out what keys the current tx has read or written.

@return an unmodifiable set of keys that have been read or written by the transaction on this
        thread.
@throws IllegalStateException if not tx in progress
@since GemFire 5.5
geode-core/src/main/java/org/apache/geode/internal/cache/LocalRegion.java