private void initializeListenerExecutor() {
    executor =
        LoggingExecutors.newFixedThreadPoolWithTimeout(1, 120, SECONDS,
            "Queued Gateway Listener Thread");
  }
Initialize the Executor that handles listener events. Only used by non-primary gateway senders
geode-core/src/main/java/org/apache/geode/internal/cache/wan/serial/SerialGatewaySenderEventProcessor.java