Problem: Article: The key aspect of a good unit test is that it checks just one portion of a program. Whether you are looking to test an existing program, or planning tests for a program that isn’t written yet, you’ll need to break it down into discrete parts (“units”). You’ll then write a unit test for each one. The definition of a “unit” varies widely depending on the type of program you are developing. A unit could be a class, but also a single function or procedure. A unit test can be used to check two kinds of scenarios. State-based testing is used to see if a program unit produces proper or expected results. Interaction-based testing, on the other hand, is used to see if a unit sets anticipated methods into action. To write a good test, you’ll need to identify what you are trying to test for, so keep one of these approaches in mind as a model. Keep in mind that you’ll need to write lots and lots of unit tests. You’ll want to run a unit test for every portion of your program. Keeping your tests simple will have several benefits:  Simple tests will help ensure that you really are testing only one unit at a time. The tests’ code will be reliable. If you have complex test code, it will be more prone to problems, making it just that harder to see bugs in the code of the program you are testing. The tests will be faster, decreasing the overall amount of time it takes to do the testing. A simple test will be readable, meaning you may see some potential problems just by looking at the code itself. Seasoned developers know that there are different ways to test a program. Unit tests are narrow, specific, and look at only one portion of a program. Integration tests, on the other hand, look at the whole program in a real environment. In other words, unit testing ensures that the individual parts of a program work, while integration testing verifies that the parts work together. Integration tests also usually require external elements, such as web servers or a database. To keep unit tests controlled, write them so that they don’t require external elements.
Summary: Map your program into units. Determine if you need state-based or interaction-based testing. Plan simple and readable tests. Differentiate unit tests from integration tests.

In one sentence, describe what the following article is about: . In marksmanship training, soldiers are required to hold their rifles so steady a hammer could fall on the barrel and the shot would still be accurate. Shooting is a matter of form, not luck or muscle strength. Practice shooting from different positions and find the one you feel most comfortable firing from, then keep practicing the others anyway. Good marksmanship involves being comfortable shooting from any of the following positions, with the basic fundamentals of shooting in place:  Standing position. In this position, you'll stand with the hip of your non-trigger hand pointing at the target, and will support the rifle with your elbows in tight to your torso to make it as comfortable as possible. This is the most difficult position from which to make accurate shots. Kneeling position. This is a steady position that allows you to balance your supporting hand on your knee, making it one of the most comfortable and steady positions from which to shoot. Sitting position involves sitting cross-legged, balancing both the shooting and the supporting elbows on each of your knees. While the sitting position is somewhat less comfortable than it may seem, it's extremely secure, especially if you can control your breathing. Prone position. This is the most accurate shooting position for many shooters, offering you the most support possible, allowing you to use your close proximity to the ground to steady yourself. When you pick up the gun, always be sure to check and double-check that the gun is unloaded. Only load the gun when you're set and ready to fire. Pick up the gun, keeping the barrel pointed downrange, and place your hands on the handgrip and the stock correctly. Hold the handgrip, just behind the trigger, with your dominant hand. Keep your hand well back of the trigger when you’re first getting situated. Your finger should be nowhere near the trigger. Up-turn your palm and use your fingers to create a “V” with your steadying hand. Seat the stock of the gun into your supporting hand, about halfway between the barrel of the gun and the trigger. Experiment some with your grip to get a sense of what's most comfortable for you. Expert rifle marksmen generally support the rifle fairly close to the trigger guard, because it'll strain your muscles less to hold the gun upright. While rifles don't kick anything like shotguns, it's still important to secure the rifle in the pocket created by your shoulder and armpit, pulling it firmly into the muscle just inside of your shoulder. It should neither be resting against your gun nor your shoulder bone, but the muscle that connects them. After you've taken hold of the gun properly, get into firing position and maintain what's called "cheek to stock weld." Holding the gun properly, you should be able to let your head fall over gently to the side, letting your cheek rest against the butt of the rifle and align your eye with the sights. If you need to readjust some, carefully readjust and resettle yourself to make the position comfortable. Once your eye is aligned, you need to learn to aim the gun properly. The process is slightly different, depending on the variety of sighting mechanism included with your rifle. Some rifles have telescopic sights, commonly referred to as "scopes" while other rifles feature simpler bead-style sights on the top of the barrel.  Bead-style sights are aimed by lining up the bead at the very end of the barrel even with the port farther back on the gun. The bead at the end needs to be the same height and just between the "V" created by the port. Usually, these are marked with green or red luminescent dots. When you're firing, focus your eye on the bead, not on the target itself. Telescopic sights are like telescopes mounted on the top of the barrel, which usually feature a cross-hair style sight imposed on the magnified image. Shooting involves lining up the point at which the lines cross and training it directly on what you want to shoot. It'll take some practice to line up your eye accurately with the sight, staying far enough back to get an accurate sight picture.
Summary:
Find your steady position Hold the handgrip in your trigger hand. Balance the stock in your supporting hand. Pull the butt of the rifle into the pocket of your shoulder. Drop your cheek to the rifle. Align the rifle sight.