Sending commands and getting a result back via Hazelcast

gistfile1.java

public Map<node,result> execute(Command command) throws Exception {
    if (command == null) {
        throw new Exception("Command store not found");
    } else {
        //store the command to correlate it with the result.
        commandStore.getPending().put(command.getId(), command);
        //I create a timeout task and schedule it
        TimeoutTask timeoutTask = new TimeoutTask(command, commandStore);
        ScheduledFuture timeoutFuture = timeoutScheduler.schedule(timeoutTask, command.getTimeout(), TimeUnit.MILLISECONDS);
    }
    if (producer != null) {
        //send the command to the topic
        producer.produce(command);
        //retrieve the result list from the blocking queue.
        return command.getResult();
    }
    throw new Exception("Command producer not found");
}