In this example, we will develop a logging library.
Please note that this is only an example, used to introduce you to some software engineering challenges and techniques. In a real product, you would use an existing logging library , such as log4j, logback, and/or slf4j.
We start with a simple Main class that uses a print statement to print debug messages to the console.
New Requirement: We want to easily turn debug messages on/off.
Let's see how we handle this case in step 2.