How should I know? I can't see your code. It's up to you to take a look at your code (whether you wrote it or not) and provide information to us. I'm not trying to be rude, but this is a Q&A site for programmers. We require users to have a certain level of familiarity with the process. — Chris 14 secs ago

Not here there isn't, for the reasons I've explained. So does the help center. You might try Software Recommendations, but be sure to read their guidelines to make sure your question is appropriate there before posting it. — Ken White 37 secs ago

See the Open letter to students with homework problems. Stack Overflow does not accept homework dumps. What is your question? — Sebastian Simon 10 secs ago

Check in with the software recommendations stack. Recommendations are of topic for this forum. Or even check the nugets libraries. — Hursey just now

Please acknowledge that asking for recommendations like this is explicitly off-topic on this site. Please try over at Software Recommendations instead. — Filburt 38 secs ago

Try to look at this topic or this topic — Nikolay Fomichev 46 secs ago

Please be aware that this site is not a free code writing service. Nobody will do your homework for you. Read this: How to Ask and this: softwareengineering.meta.stackexchange.com/questions/6166/… — Jabberwocky 14 secs ago

Welcome to stackoverflow, you have just pasted your requirements and expecting someone to do work for you. That's not how this site works, kindly read How do I ask and answer homework questions? and Open letter to students with homework problems and Help sections. — Pradeep Simha 40 secs ago

I’m voting to close this question because it belongs to softwareengineering.stackexchange.com — Corentin Pane 5 secs ago

Thanks for the reply. SO I can not just use the transaction. I'm still using the free version. But if my app becomes popular, I will use the cloud function. But, if firebase programmers do not know what to do, adding a way to set a list of data paths we will want to read and write before starting a transition will be pretty usefull. — qqchose 1 min ago

@Shark: If optimizations "break your code", it was already broken and just happens-to-work in some cases, e.g. with debug builds that store / reload everything to memory between statements. (Java doesn't have an equivalent to un-optimized builds, so I guess Java programmers never get the wrong idea that they code works in the first place in as many cases. Of course as an answer on the querent's linked previous question indirectly shows, you could by chance get release/acquire synchronization from lack of compile-time reordering on x86, and have it break on ARM / everything else.) — Peter Cordes 5 secs ago

softwarerecs.stackexchange.com — Jab 27 secs ago

"Premature optimization is the root of all evil" - You aren't giving nearly enough information to tell, whether this is in any way a performance bottleneck, or not. — ASDFGerte 6 secs ago

It gets confusing if you do it that way (for programmers and, I think, some of the tools). I try to avoid it — Flydog57 18 secs ago

And most projects involved average developers that do not know when not to use it. Therefore it would be wiser to just impose a hard limit of totally forbidding it rather than arbitrary say it is ok sometimes. If you do that, then you will just find it is impossible to regulate and things will eventually spiral out of control. The real danger are non native Java programmers and millennials coming to the language and of course is the first thing they learn to use because it "so easy". Not really. — mmm just now

Hi, Please read How to ask homework question and Open letter to students with homework problems to learn how to ask a good homework question. — Akshay Sehgal 7 secs ago

Ummm..... the software recommendations stack? softwarerecs.stackexchange.com — Hursey 58 secs ago

See is there any reason to use the var keyword? — jarmod 30 secs ago

I believe this question may work better on Software Engineering or Code Review, due to how questions about code design tend to draw in opinionated answers, which are not allowed here. See meta.stackoverflow.com/questions/256663/… — spicy.dll 41 secs ago

A question having multiple answers is not a problem at all, since each answer can be judged as to how well it answers the question. The issue with a question like "is there a good reason programmers should care about initialization types?" is that it's very hard to objectively judge any answers. I think your question could be improved so that it invites concrete, objective answers, but in its current form, I'm afraid I don't think it works. — cigien 21 secs ago

@zipzit Not sure that's fair. The OP did make an effort to implement quite a bit of it. The homework questions which deserve ignoring are the ones which just list the requirements and show absolutely zero effort, just wanting a free ride. Please read How do I ask and answer homework questions? and Open letter to students with homework problems if you haven't already. — ADyson 29 secs ago

I’m voting to close this question because this site is not a product support site for all things Java. It is a question and answer site for programmers, and you are welcome to ask about issues with your program that you are creating. — Hovercraft Full Of Eels 23 secs ago