EntryEventImpl createTransactionCallbackEvent(final LocalRegion re, Operation op, Object key,
      Object newValue, TransactionId txId, TXRmtEvent txEvent, EventID eventId,
      Object aCallbackArgument, FilterRoutingInfo filterRoutingInfo,
      ClientProxyMembershipID bridgeContext, TXEntryState txEntryState, VersionTag versionTag,
      long tailKey) {
    return txCallbackEventFactory
        .createCallbackEvent(re, op, key, newValue, txId, txEvent, eventId, aCallbackArgument,
            filterRoutingInfo, bridgeContext, txEntryState, versionTag, tailKey);
  }
Removing the existing indexed value requires the current value in the cache, that is the one
prior to applying the operation.

@param entry the RegionEntry that contains the value prior to applying the op
geode-core/src/main/java/org/apache/geode/internal/cache/AbstractRegionMap.java