@Override
    protected void sendMessage(Connection cnx) throws Exception {
      getMessage().clearMessageHasSecurePartFlag();
      getMessage().send(false);
    }
Does a rollback on the server for given transaction

@param pool the pool to use to communicate with the server.
@param txId the id of the transaction to rollback
geode-core/src/main/java/org/apache/geode/cache/client/internal/RollbackOp.java