Thursday, July 28, 2016

Writing Effective Exception Descriptions


Writing exception descriptions are not really taught in programming classes but are vitally important in the field.  Namely if you need to refine your descriptions to find a problem it can lead to multiple pushes to a production environment before you actually fix the problem.  Depending on the issue this could waste valuable time.

Between reading about how to write good exception descriptions from various companies and my personal experience I've accumulated the following tips to share.  Note that most of the time exception text bubbles into your log files so some references to log files will be mentioned as well.

Be Layer-Centric

If you catch an exception and re-throw, describe the problem in the terms of the current (throwing) layer.  As an example, if you are writing TCP/IP library code and catch an IP exception, state your TCP problems.  If you are (ab)using TCP for Inter-Process Communication (IPC), state the process you are trying to reach.  I have mistakenly thought there was a networking error when a program couldn't connect to localhost before.

Not a Singleton?  Include your object ID

Imagine a case where there is a complex object with invariants.   With two instances of the class logging at the same it could easily appear to violate it's invariants or demonstrate impossible behavior.  Imagine your TCP class logging that it closed the connection and then that it read data successfully - this could be very confusing.  With object IDs you would log that client 1 closed the connection and client 2 read successfully - this makes much more sense.

Multi-threaded?  Include your Thread ID

Some times you need to trace the execution flow in a particular thread.  If you do not include your Thread IDs this is an impossible task to do via the logs.

Don't Trust Library Exceptions

Frequently exceptions generated by library, module or component code is not very descriptive.  Continuing with the networking examples I've had many HTTP exceptions with no more description than "Bad Request".  Note the lack of IP address, host name, or port.  Given that exceptions turn into logs that then can go into various applications (e.g. Splunk) I think the descriptions are generic due to security concerns.

Include Some Variables

Try to include one or two other things to help you track down a problem, knowing WHAT from following the recommendations above won't necessarily help you figure out WHY.

Make it easy

When you write your subclass consider including a String.format style constructor.  This would let you avoid having to do a String.format call on every exception you need to throw.  Alternatively you could make an ExecptionDescription builder that includes the object ID and Thread ID automatically.


In conclusion if you plan ahead and write descriptive exception messages that let you track the instance, the thread and some internal state you will be able to diagnose (possibly critical) issues much faster.

Tuesday, July 12, 2016

Overview of JSON Libraries and How to Choose a Library


It's good to be back.  The blog had an expected hiatus while I moved to a new city, also around Seattle.


Many of my posts are about overcoming unexpected difficulties when using some software library or module or another.  I decided to take a step back and try to select a quality module in the first place.  This is my analysis of the JSON libraries I was able to find and can count as a how-to to select a library in general.

The short result is that if a Library is in Maven, you can look at Maven Central to see how popular a library is and how frequently it is updated.  Then you can use one of the most used and updated libraries out there.  You can also consult StackOverflow.  Here are some examples.

The List

  • JSR 353 - We have javax.json-api and org.glassfish/javax.json.  Out of these two the
    This could be you!  Image from

    org.glassfish one has more users and more updates (version 1.0.4 vs 1.0), so it is the winner so far.
  • Fast-XML Json Parsing / Jackson has many more updates (version 2.8), is far more used and the updates are fresher.  That makes it the winner so far.
  • JSON-Simple is comparable to the JSR 353 libraries.  If not for the Jackson library you could choose based on how well prior Google libraries have worked vs Oracle libraries.
  • org.json falls between Jackson and the JSR 353 libraries with about 700 users and a release in Feb of 2016.
  • Google GSON has about 2000 users and was updated last month.  This puts it on par with Jackson.
  • quick-json has 0 users!  This would make it almost unqualified even if there were no alternatives.
  • JsonPath - Lastly, JsonPath has a couple of hundred users.


Now, you may be skeptical of the Wisdom of the Crowd (e.g. appeal to the people or groupthink) but more users means that there is a higher chance someone found the same problems that you have.  Even in this day and age Googling an error string can still produce 0 results.
Based off of this my project is using Jackson and hasn't had any problems with it for months.

Next Steps

Once you have your JSON library picked out, how do you manipulate it?  I've had good luck using, although in the options you have have it add annotations... which makes it a non-POJO technically...

Wednesday, May 18, 2016

Java Multithreading in Practice: Part 3

Introduction - The Saga Continues

In Part 1 we discussed presenting a cleaner interface to Java 6's ExecutorService and ScheduledExecutorService.  In Part 2 we discussed ensuring that the system doesn't eat / ignore exceptions in threads.  In Part 3 we will go over reusing the thread pool... because that's the point of a thread pool.


We don't read ALL of the documentation on a given class, we read parts and whatever the IDE gives
Thread Pool, not to be confused with Deadpool
us on a mouse-over.  This habit led me to reading the method-level documentation of ExecutorService but not the class-level documentation.  This is important later.


The ExecutorService will have an equivalent of Thread.join(), and then be re-usable since that is the whole point of a thread pool.  A quick skim of shutdown() says to use awaitTermination().  Upon reading the full docs of awaitTermination() it appears that this is what I am looking for.


Running threads after a while mysteriously fail with a ThreadPool size of 0.  I never set the size to 0, why would it do that?  After struggling with this and creating more unit tests to narrow the problem down for a full day (full day) I find that awaitTermination() terminates the WHOLE POOL instead of terminating the currently running threads.  What's the point of having a terminated pool?  Isn't that what close() is for?  Does this have a close()?  Why not?  Maybe because it is in the package instead of java.concurrent?  Again, the entire point of having a thread pool is to reuse the threads!


In addition to needing to keep a List<Callable<Void>> I need to keep a List<Future<Void>> and loop through all of the Futures to cancel() each one.  WHAT?  Again, nothing in the documentation of awaitTermination() says that it terminates the thread pool itself.  That is buried in the class level documentation.  I end up adding a cancelThreads() method to our custom ThreadPool object leaving us with a final API like the following:
public class ThreadPool {

    ThreadPool(int size) {...}

    void add(Runnable) {...}

    void add(Callable<Void>){...}

    void clear(){...}

    boolean isEmpty(){...}

    void runSynchronously(){...}

    void runAsynchronously(){...}

    Callable&ltVoid> toSafeCallable(Callable<Void&gt){...}

    Runnable toSafeRunnable(Runnable){...}

    void cancelThreads(){...}

    void close(){...}

Tuesday, May 10, 2016

Technology Gone Terribly... Right

I'm not an Amazon fan-boy.  I worked there as a contractor  for 8 months and still didn't start using Amazon in my personal life.  I may be forced to subscribe to Amazon Prime to get Dr. Who, but that will be very begrudgingly.

However, Amazon Web Services is a true gem in an otherwise frustrating field.  I worked with AWS for a 3 month stint about two years ago and had to use some AWS services at my current job (p.s. my Google+ job history is outdated) and getting both the Simple Notification Service and the Simple Storage Service only took me a day.  No real hassles, surprises or gotchas.

I usually write about how to deal with things going wrong, but for once I'm writing about something going right.

It isn't nearly as interesting, is it?

Tuesday, May 3, 2016

You're Killing Me Spring: "Singleton" Scope


I generally try to avoid traditional Gang of Four Design Pattern Singletons.  In Java they are only guaranteed to be singular per running Java Virtual Machine, don't scale to a clustered environment, can be serialized / deserialized to create a duplicate even in the same JVM and are generally the OOP version of global variables.
However, in a given project I had an exception to this rule.  I had an object that was using a single TCP port going into an environment where only one instance would be deployed per machine so I thought to myself that I would use the Singleton pattern.


Created at imgflip, original image copyright Dos Equis.
I have had problems with Spring before.  Specifically I was working with Spring Web Flow 3 years ago and had some configuration (including setters) in my beans.xml file, in my Spring Web Flow xml file I imported the (Singleton) beans defined in the beans.xml file.  However, instead of importing the bean it created a new instance of it, and on top of that it didn't call any of the initialization configuration in the beans.xml file leading to null pointer exceptions.  It took me three weeks to track this down.  I was working for myself (e.g. that time was on my own dime) and I ragequit Spring in favor of Google Guice.  For this project I was forced into using Spring so I had the following Hypothesis.


"Verify that Spring is treating Singletons correctly because it's been unreliable, surprising and buggy in the past."  In code-form it was a standard Spring @Service in the default Singleton scope with a check in the constructor (see Further Reading for other reasons to do this) to blow up if the constructor is called twice.  In addition, Spring makes you have a public constructor even for your Singletons so blowing up can avoid programmer error of someone later trying to just call new ExampleSingleton.
// implied Spring Singleton Scope
public class ExampleSingleton {

    // should only be called once by Spring
    public ExampleSingleton() 
        if (instance != null) {
            throw new IllegalStateException("Singleton constructor called twice!");


As you may have guessed from the image, Spring was attempting to create the "Singleton" repeatedly and blowing up with the IllegalStateException.  From doing some research I found that @ComponentScan was behaving strangely.  It turns out that if you have multiple Spring @Configuration classes and if they overlap on a package (e.g. @ComponentScan(basePackages = {"com.yourcompany"}) and another with @ComponentScan(basePackages = {"com.yourcompany.utils"}), Spring will (re)create all of the Singletons in the overlap (in this example com.yourcompany.utils) twice.  I found this surprising and very strange.  In addition, the same link mentions that Spring only promises that a Singleton will happen once per ApplicationContext, and Servlets usually have more than one.


I concluded that you can't trust Spring to honor the @Singleton contract and to manage my instances myself.  After doing more research I found that in Java the best way is to have a SingletonFactory.  I ended up having a base class called SpringSingleton, which has the documentation on why all of this is necessary and a protected constructor that keeps track of which sub-classes have been instantiated with a Set<SpringSingleton> that is accessed in a synchronized block.  In addition the @Configuration classes have an @Autowired SingletonFactory and @Bean definitions that get the beans from the SingletonFactory.  All in all it still isn't foolproof for Serializable Singletons (see below) but does a great job otherwise.  There is more complexity (4 classes for the simple case) but new Singletons end up being easy to implement and work correctly.  I would post the code but I made it at work so the company has copyright.

Too bad I couldn't just have @Component on a class with the default scope and have it work right.

Further Reading

You can abuse an enum in Java to ensure a "serializable" Singleton can't be easily duplicated but that has some drawbacks.  Given that you can invoke even a private constructor via the Java reflections API you will still want to verify that your Singletons are only being called once (or at least post a warning in the logs).


There was an issue with the site CSS where black lines would appear over an image. This has been fixed.

Wednesday, April 27, 2016

Java Multithreading in Practice: Part 2

In the previous Java Multithreading in Practice we discussed simplifying the base Java API for increased readability and reliability.  However, after further analysis catching exceptions was still not full-proof.  The end-user (of the API) would still need to remember to catch Exception in their Runnables and Callable<Void>s.  A working solution is to automatically do that internally in the custom ThreadPool class (not Java's ThreadPool class) with two protected methods, toSafeRunnable(Runnable) and toSafeCallable(Callable<Void>).  All these do is wrap the passed in argument in try catch block, catch Exception and log it as an error.  This lets the end user not have to worry about exceptions being lost in the system.


In-line code is now monospaced and green to let it stand out. I hope that this helps people read the blog!

Wednesday, April 20, 2016

Java 8 Multi-Threading in Practice

Dealing with multithreading and race conditions is a famously hard and tricky subject for computer science.  On top of that, Java has some odd and unexpected implementation details in this area as well.

The first thing I noticed is that my engine was taking over 40 seconds to shut down after a Ctrl-C.  Where was the interruption going?  It turns out that the forEach lambda, apparently as part of it's functionalness, completely ignores interruptions until it is completely done with its tasks.  This means that the new stream APIs are not useful for long-running tasks (e.g. the kinds of tasks you want to run in parallel in the first place) without a work-around, such as checking manually if a thread is interrupted or a thread pool is shutdown (see below).

The second thing I noticed that was when a Callable was being executed by and the executor service was shut down, the Callable's Thread.currentInstance().isInterrupted() would return false, even if actively checked!  As a work-around I had to pass a reference to the executor service into the Callable and check ExecutorService.isShutdown() instead.  In my particular code-base this caused a circular reference but the modern garbage collector uses mark-and-sweep instead of reference counting so no memory leaks happen.
It could be worse [1].

Lastly the APIs can't decide if they want Runnables or Callables.  ExecutorService.invokeAll() only takes Callables and ScheduledExecutorService.scheduleAtFixedRate() only takes Runnables.  Of course I have the same logic that sometimes needs to be run all at once and sometimes needs to be run repeatedly so I need to convert between the two.  It looks like if an exception does bubble out of a call, it is simply ignored.  This caused some strange system behavior until I made a habit of catching Exception and logging an error.  Of course, we hate to catch Exception.  For this reason I strongly prefer Callable, despite the debate on StackOverflow.

The solution was to create a ThreadPool class and ScheduledThreadPool sub class in my project's utils module to simplify all of this complexity and automatically convert between Runnables and Callables as needed.  After I made these classes and had the code base use them it was easier to think about how the system worked instead of being mired in the details of the Java API.

[1] Dragon Riders of Pern by FanDragonBall

Wednesday, April 13, 2016

LocalDateTime Is Not Local!

No one ever has problems with Dates and Times!  (Y2k, 2038, 10,000)

Java8 dates and times were supposed to be a lot easier and designed by the Joda-Time guys.

One problem, after struggling for a full working day - LocalDateTimes are NOT Local!  Maybe in the sense of localized?  They are definitely UTC, not your local timezone.  Looking back at it, it says that it doesn't capture timezone information in the docs, but I didn't look at the docs because I thought that the name was blindingly obvious.

Copyright BBC
I was pulling my hair out when I wrote a function todayAt that returned a date that didn't register as today.  A time at 3:45 PM was being converted to 2 AM UTC (the next day) because LocalDateTime wasn't local.  I was looking for ZonedDateTime.

As they say, there are two hard things in Computer Science: caching, naming things and off by one errors.

Tuesday, April 5, 2016

What's the Goal of AI? and Bad Decisions

The implicit, if not explicit goal of artificial intelligence (AI) has been to create "human-like" intelligence.  The recent debacle of is the first time something has seemed to become strangely close.

That is to say, the aim of the project was to simulate someone in their late teens.  People in their late teens tend to make poor decisions, especially to go along with what people around them believe.  (I'm no exception and had quite a long "hippie phase" including being Vegan for 3 years.)
Vegan super-powers from Scott Pilgrim vs. the World

Do we really want to make an AI like us, with all of our foibles and cognitive distortions or are we going to pull the plug as soon as one adopts unconventional, minority or fringe views?  Will we use the phrase "it's just going through a phase"?

People do dumb stuff and usually learn from it and course correct... sometimes they make the same mistakes for decades on end until the very end.

I would think that if we are doing it right we will have a crop of AIs just as diverse as ourselves, including the bad stuff.


I was in the hospital so missed a week or two of Tuesday posts.  It happens.

Tuesday, March 22, 2016

Spring Annotations: Using Constructor Arugments with @Autowired


I've struggled for weeks with wanting to use a constructor with arguments along with Spring Annotations (in particular @Autowired) but most blog posts and tutorials say that this isn't possible or needs to use Spring Expressions.


There has got to be some way to do this.  The alternative I have been using was to have an empty object autowired in and then manually run a bunch of setters to inject the required configuration.  This ends up being error prone and verbose to verify (e.g. every public method has to check that the required fields are not null).


After searching the web for a long time I finally found that you CAN use multi-argument constructors if you refrain from using the @Component or @Service annotations and instead create the classes in a @Configuration class with @Bean annotations.  After creating a class (manually, with new) you can autowire it by using AutowireCapableBeanFactory.autowireBean(Object) method.


My code is a lot more readable and simple now, and let me find a few subtle bugs that did not turn up in the unit tests.  I ended up with complex object creation logic, but it is out in the @Configuration classes instead of inside of the core objects.  I am much happier with this situation.

Tuesday, March 8, 2016

Java Lambdas and Interrupted Exceptions

I couldn't figure out why my application was taking 40+ seconds to shut down.  It turned out that a long-running process was in a Lambda expression and was completely ignoring the owning thread being shut-down.  Changing the code to a foreach loop fixed the problem.

It looks like foreach loops are still useful in Java 8 after all.

Short post today - not feeling well.

Wednesday, March 2, 2016

Great for Karaoke: Hack Star

I was sick and overworked on Tuesday (who isn't!), so this slightly-late post it may be a bit off topic.

It's a parody, in the spirit of Weird Al or James@War, of Nickleback's Rockstar: Hack Star.

It isn't 100% polished, but it's been in my head since 2006!  If you look at the lyrics, it's roughly the 6 - 8th paragraphs.

We all want to be big hack stars,
With the Internet using all our Zips and WARs.
We'll have so many gadgets it'll be real neat,
No one will understand us cuz we'll all speak Leet.
And, we'll have the cash to live like Tzars,
hard work and talent will take you real darn far.
We'll have our competition ripping out their hair,
they'll complain to congress that it's just not fair,
and well,

Hay hay I want to be a hack star
Hay hay I want to be a hack star

We'll make apps so leet they'll augment your senses,
Me and my homies have our certs from Mensa.
I'll hack so hard that it takes up half my brain,
I'll hack so hard that drives me half insane.

Hay hay I want to be a hack star
Hay hay I want to be a hack star

Tuesday, February 23, 2016

Windows 10 for the First Time


 Here's another Tuesday post!

I got a top-of-the-line new laptop (at Walmart...) that I've been delaying for far too long.  My four year old laptop barely runs ONE tab in Chrome.  I've had to revert to the old (original!  From 2006!) gmail settings a few times just to get anything done.

Original author unknown
In the same spirit as OSX for the First Time, here is Windows 10 for the First Time.


As I mentioned before, I've been using MS-DOS / Windows for a long time and was fortunate enough to know enough to avoid Windows ME and Windows Vista.  It's been said that Microsoft gets every third product right (unknown attribution), so after Vista and Windows 8 I have moderate expectations for Windows 10.

First Day

The first day went pretty well.  The initial set-up process was really smooth, it connected to my WiFi and the internet just fine and there were not a whole bunch of updates to download right off of the bat.  I tried using YouTube with the new Edge Browser and it worked OK for the first half-hour, after that there were unforgivable errors (e.g. not being able to click inside of the video box).  I mean, who messes up Clicking these days!  I was not impressed.

Somewhere in there I asked "Cortana" how big my hard drive was... she sent me to Bing... I was, again, not impressed.  Also, it's just a text box.  No pretty face or anything!

Cortana from Halo - Copyright Microsoft
I downloaded Firefox at around the hour mark of "real usage" (e.g. not setup time).  Firefox was able to run video just fine on YouTube with no problems.

Second Day

Second day, I needed to print and scan with my networked printer (hp deskjet 2542 wireless all-in-one printer).  Printing worked great and the default drivers installed flawlessly and "just worked" for printing.  +1 to Microsoft, who is now shooting at 1 win and 2 losses.  Funny thing, the biggest hastle was figuring out how to bring up Notepad... I told Cortana to "Open Notepad" after futzing with the new Windows Button in the lower left and at least that worked.  I'll put that as 1 lose for the Windows Button and one win for Cortana, putting us at 2 wins and 3 losses.

Next up was scanning.  I had to install the custom HP software, which claims to be Windows 10 ready, in order to scan.  It kept being unable to setup the printer... which is already set up.  It said to uninstall the HP printer driver and restart the printer... and was then still unable to setup the printer.  Three hours later I booted up my Windows 8 dinosaur and scanned using that.  Epic fail for device drivers!  It was so frustrating it drove me to drink (a reasonable amount).  Windows 10 is now looking at 2 wins and 4 losses.


Avoid using Edge, peripherals and Cortana and it is working OK.  Microsoft usually has a long time frame in mind when releasing a new OS, so it's usually two years until a new OS is generally usable and Windows 10 looks to be no different.  Keep your old OS so that you can have working 3rd party device driver!  Final judgement 4.4 / 10, compared to the usual Microsoft products 8.0 / 10.

Why do I use Windows?  What's that phrase, devil you know?

Tuesday, February 16, 2016

Are these Images Similar? Simple Machine Vision with a Perceptual Hash



At my job I had an actual requirement to tell if a given image was similar to a previous image (to detect a bad video input).  That was it, no background or suggestions on how to go about it.  This sounded a lot like Machine Vision to me, which is somewhere under the Artificial Intelligence (AI) umbrella.

I promptly started to freak-out (see image at right).


I quickly came across the concept of a Perceptual Hash during my first Google searches.  This led to finding first a C (++?) open-source library called pHash.  This prompted a further search for a Java open source library, which led to a Stack-Overflow question and a small Java class to take care of the heavy lifting.  The docs of this further linked to another source of inspiration on Hacker Factor for that author.


This class, ImagePHash by Elliot Shepherd, will work as-is without me having to delve into the gory details too much (the Hacker Factor link provided an excellent overview).


It worked really well!  I just put in some tweaks to Springify it (see Java Papers tutorial on Spring annotations for details) and use the logging framework the project uses instead of System.out calls and I was getting back the "distance" between two perceptual hashes in no time.

I still had to interpret these results because my code base needed a yes-no answer.  So I downloaded about 5 images from the Internet that were similar to my original image, and cropped the original image as well.  I found that a distance of 8 was a good cut-off for sameness, e.g. for a distance of 8 or below I would consider the images the same.  This would count the cropped image as the same, but not similar but looks different to me images.

I would be more specific but it was done on company time so I can't go into details too much (see also: Non-disclosure Agreements).


The whole loop took about a day and wasn't too scary once I go into it.  I'm glad that I didn't try to re-invent the wheel and that the class worked!

Tuesday, February 9, 2016

OSX for the First Time


Here is this week's Tuesday post.

I started a brand new job and one thing didn't come up in the interview: they are a Mac shop.  I already accepted the offer, so I decided to learn how to use this MacBook Pro (I think).  It's definitely OSX.
You may be too young to have seen one of these.


I'm a long time user of Windows, and started back in the MS-DOS days of having to make a custom 3.5" boot disk to have enough 640k memory (which Ought to Be Enough for Anyone) available to play games.  Needless to say, I'm (unfortunately) invested in Windows, and have some pretty cool stuff that I can do with my mouse.
I'm not trying to start a flame war, one way or another.

First Day

The first day was mostly struggling with the keys and initial setup.  It isn't Ctrl-C to copy, it's command(⌘)-C.  Basically, everything you want to do with Control on Windows you do with Command on Mac... except for stopping a process on a command prompt, that's still control-C.

The control key goes from best-friend to too-busy-to-keep-up status.

Also, the Function Keys aren't the Function Keys by default.  To press F3 you have to press fn-F3.  I've seen similar setups on Laptops but they usually have a "fn-lock" key.  I'm a programmer, so I use F3 (Eclipse -> Go to Source Declaration) about 20 times a day.  I've used a "non-fn" key about 5 times.

First Week

I discover the oddness and joy of the Magic Mouse.  It looks like a mouse that forgot to finish getting made, and I have to configure it to be able to right click, but I've started liking it.
I'd still like to Copy and Paste using my mouse like I have setup on Windows, but oh-well.

Apple Magic Mouse - See Credits section for attribution.
I have a three monitor set up (laptop screen and two monitors) - more than I've ever had on a Windows box.  This is really nice!  I have my command prompt on my small lap-top screen on the right, IM / Email on my left hand screen and the rest in the middle.

I had to struggle with the Dock (I was using a 3rd party Dock on Windows, so this was easy in general) when it would seemingly randomly move to another monitor.  It turns out, mousing down off of the screen brings the dock to that screen.  This can be done quite easily on accident, but once I know what's going on I can bring it back to my main screen pretty easily.

My left monitor starts randomly going black, and I look at many different solutions to the problem.

The system in general is pretty powerful (I think the company got a top-of-the-line model).

First Month

I upgrade the OS to El Capitan (trying to fix the screen issue as mentioned above), I thoroughly look at all of the System Preferences and I'm able to do regular, day-to-day work on it.


After a month of work-day use, it's starting to fade into the mental background.  It doesn't do unexpected things and it doesn't need excessive updates.  I'm not a 'convert' and probably wouldn't pay the extra money for a Mac.

It's definitely better than a "standard" Windows pre-install with McAfee (no link on purpose) and the other bloatware.


For the small handful of people reading these, thanks!  You'll continue to find good content.
I'm assuming these reads aren't just bots...


Magic Mouse Image: By Yutaka Tsutano from Lincoln, United States - Magic MouseUploaded by Mewtu, CC BY 2.0

Wednesday, February 3, 2016

Tuesday, February 2, 2016

Blog Reboot: For SCIENCE!

It has been a heck of a year since the last time there was a new post here.

As mentioned on the Thirteen Blog Cliches on Coding Horror no one likes explainations of why a Blog hasn't been consistent.

Moving forward the posts are going to get a little more Computer Science-y, not in the hard-to read way but in the basic core of reproducing / verifying another persons claims.

In practice, I go through a lot of material that I get off of the web and a lot of times there are gotchas or caveats that the original author did not mention.  They will be mentioned and refined here.  There will be basic sections on hypothesis, results and conclusion.  Nothing super-heavy weight.

I'll keep this short: like I said, nothing super-heavy weight.