In build.gradle, the dependencies on distZip and/or distTar causes
the shadowJar task to generate a second JAR file for which the
mainClass.set("seedu.duke.Duke") does not take effect.
Hence, this additional JAR file cannot be run.
For this product, there is no need to generate a second JAR file
to begin with.

Let's remove this dependency from the build.gradle to prevent the
shadowJar task from generating the extra JAR file.

Some parts of the code assume certain conditions hold, but these assumptions are not explicitly enforced. This could lead to errors or unexpected behavior during execution if those assumptions are violated.

Without enforcing these conditions, the code may fail silently, which could make debugging more difficult and reduce code reliability.

Let's add assert statements to verify critical conditions at runtime. This ensures that assumptions are checked and provides immediate feedback if they are violated.

Using assert is appropriate here because it adds minimal overhead and is disabled in production, keeping performance unaffected.

The program contains blocks of code that are no longer executed or necessary. These portions of the codebase add unnecessary complexity and make it harder to maintain and read the code.

Dead code can confuse developers and lead to misunderstandings about the program's behavior. It's important to keep the codebase clean and focused only on what is required.

Let's remove the dead code to simplify the codebase, reduce maintenance overhead, and improve overall readability.

Removing dead code helps avoid future bugs and keeps the project lean.